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5.3. 双向队列（ ）
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0. 写在前面
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0.4. 一起参与创作
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1. 引言
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1.1. 算法无处不在
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1.2. 算法是什么
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2. 计算复杂度
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2. 计算复杂度
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2.1. 算法效率评估
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2.2. 时间复杂度
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2.3. 空间复杂度
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2.4. 权衡时间与空间
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2.5. 小结
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3. 数据结构简介
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3. 数据结构简介
< / label >
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< a href = "../../chapter_data_structure/data_and_memory/" class = "md-nav__link" >
3.1. 数据与内存
< / a >
< / li >
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3.2. 数据结构分类
< / a >
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< a href = "../../chapter_data_structure/summary/" class = "md-nav__link" >
3.3. 小结
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4. 数组与链表
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4. 数组与链表
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4.1. 数组（ ）
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4.2. 链表（ ）
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4.3. 列表（ ）
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< a href = "../../chapter_array_and_linkedlist/summary/" class = "md-nav__link" >
4.4. 小结
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5. 栈与队列
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< span class = "md-nav__icon md-icon" > < / span >
5. 栈与队列
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< li class = "md-nav__item" >
< a href = "../stack/" class = "md-nav__link" >
5.1. 栈（ ）
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< a href = "../queue/" class = "md-nav__link" >
5.2. 队列（ ）
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5.3. 双向队列（ ）
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5.3. 双向队列（ ）
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目录
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< ul class = "md-nav__list" data-md-component = "toc" data-md-scrollfix >
< li class = "md-nav__item" >
< a href = "#531" class = "md-nav__link" >
5.3.1. 双向队列常用操作
< / a >
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< a href = "#532" class = "md-nav__link" >
5.3.2. 双向队列实现 *
< / a >
< nav class = "md-nav" aria-label = "5.3.2. 双向队列实现 *" >
< ul class = "md-nav__list" >
< li class = "md-nav__item" >
< a href = "#_1" class = "md-nav__link" >
基于双向链表的实现
< / a >
< / li >
< li class = "md-nav__item" >
< a href = "#_2" class = "md-nav__link" >
基于数组的实现
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< / ul >
< / nav >
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< / ul >
< / nav >
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< li class = "md-nav__item" >
< a href = "../summary/" class = "md-nav__link" >
5.4. 小结
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< / ul >
< / nav >
< / li >
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6. 散列表
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< label class = "md-nav__title" for = "__nav_7" >
< span class = "md-nav__icon md-icon" > < / span >
6. 散列表
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< li class = "md-nav__item" >
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6.1. 哈希表（ ）
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< a href = "../../chapter_hashing/hash_collision/" class = "md-nav__link" >
6.2. 哈希冲突处理
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< a href = "../../chapter_hashing/summary/" class = "md-nav__link" >
6.3. 小结
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< label class = "md-nav__link" for = "__nav_8" id = "__nav_8_label" tabindex = "0" >
7. 二叉树
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< / label >
< nav class = "md-nav" data-md-level = "1" aria-labelledby = "__nav_8_label" aria-expanded = "false" >
< label class = "md-nav__title" for = "__nav_8" >
< span class = "md-nav__icon md-icon" > < / span >
7. 二叉树
< / label >
< ul class = "md-nav__list" data-md-scrollfix >
< li class = "md-nav__item" >
< a href = "../../chapter_tree/binary_tree/" class = "md-nav__link" >
7.1. 二叉树（ ）
< / a >
< / li >
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< a href = "../../chapter_tree/binary_tree_traversal/" class = "md-nav__link" >
7.2. 二叉树遍历
< / a >
< / li >
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< a href = "../../chapter_tree/binary_search_tree/" class = "md-nav__link" >
7.3. 二叉搜索树
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< a href = "../../chapter_tree/avl_tree/" class = "md-nav__link" >
7.4. AVL 树 *
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< a href = "../../chapter_tree/summary/" class = "md-nav__link" >
7.5. 小结
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8. 堆
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< / label >
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8. 堆
< / label >
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< a href = "../../chapter_heap/heap/" class = "md-nav__link" >
8.1. 堆（ ）
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9. 图
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< / label >
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9. 图
< / label >
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9.1. 图（ ）
< / a >
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< a href = "../../chapter_graph/graph_operations/" class = "md-nav__link" >
9.2. 图基础操作
< / a >
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< a href = "../../chapter_graph/graph_traversal/" class = "md-nav__link" >
9.3. 图的遍历
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10. 查找算法
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10. 查找算法
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10.1. 线性查找
< / a >
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< a href = "../../chapter_searching/binary_search/" class = "md-nav__link" >
10.2. 二分查找
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< a href = "../../chapter_searching/hashing_search/" class = "md-nav__link" >
10.3. 哈希查找
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10.4. 小结
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11. 排序算法
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11. 排序算法
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11.1. 排序简介
< / a >
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11.2. 冒泡排序
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11.3. 插入排序
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11.4. 快速排序
< / a >
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< a href = "../../chapter_sorting/merge_sort/" class = "md-nav__link" >
11.5. 归并排序
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11.6. 小结
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< a href = "../../chapter_reference/" > 参考文献< / a >
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参考文献
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< / ul >
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< / div >
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< span class = "md-nav__icon md-icon" > < / span >
目录
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5.3.1. 双向队列常用操作
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< a href = "#532" class = "md-nav__link" >
5.3.2. 双向队列实现 *
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< nav class = "md-nav" aria-label = "5.3.2. 双向队列实现 *" >
< ul class = "md-nav__list" >
< li class = "md-nav__item" >
< a href = "#_1" class = "md-nav__link" >
基于双向链表的实现
< / a >
< / li >
< li class = "md-nav__item" >
< a href = "#_2" class = "md-nav__link" >
基于数组的实现
< / a >
< / li >
< / ul >
< / nav >
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< / ul >
< / nav >
< / div >
< / div >
< / div >
< div class = "md-content" data-md-component = "content" >
< article class = "md-content__inner md-typeset" >
< a href = "https://github.com/krahets/hello-algo/tree/main/docs/chapter_stack_and_queue/deque.md" title = "编辑此页" class = "md-content__button md-icon" >
< svg xmlns = "http://www.w3.org/2000/svg" viewBox = "0 0 24 24" > < path d = "M10 20H6V4h7v5h5v3.1l2-2V8l-6-6H6c-1.1 0-2 .9-2 2v16c0 1.1.9 2 2 2h4v-2m10.2-7c.1 0 .3.1.4.2l1.3 1.3c.2.2.2.6 0 .8l-1 1-2.1-2.1 1-1c.1-.1.2-.2.4-.2m0 3.9L14.1 23H12v-2.1l6.1-6.1 2.1 2.1Z" / > < / svg >
< / a >
< h1 id = "53" > 5.3. 双向队列< a class = "headerlink" href = "#53" title = "Permanent link" > ¶ < / a > < / h1 >
< p > 对于队列，我们只能在头部删除或在尾部添加元素，而「双向队列 Deque」更加灵活， < / p >
< p > < img alt = "deque_operations" src = "../deque.assets/deque_operations.png" / > < / p >
< p align = "center" > Fig. 双向队列的操作 < / p >
< h2 id = "531" > 5.3.1. 双向队列常用操作< a class = "headerlink" href = "#531" title = "Permanent link" > ¶ < / a > < / h2 >
< p > 双向队列的常用操作见下表，方法名需根据特定语言来确定。< / p >
< p align = "center" > Table. 双向队列的常用操作 < / p >
< div class = "center-table" >
< table >
< thead >
< tr >
< th > 方法名< / th >
< th > 描述< / th >
< th > 时间复杂度< / th >
< / tr >
< / thead >
< tbody >
< tr >
< td > pushFirst()< / td >
< td > 将元素添加至队首< / td >
< td > < span class = "arithmatex" > \(O(1)\)< / span > < / td >
< / tr >
< tr >
< td > pushLast()< / td >
< td > 将元素添加至队尾< / td >
< td > < span class = "arithmatex" > \(O(1)\)< / span > < / td >
< / tr >
< tr >
< td > pollFirst()< / td >
< td > 删除队首元素< / td >
< td > < span class = "arithmatex" > \(O(1)\)< / span > < / td >
< / tr >
< tr >
< td > pollLast()< / td >
< td > 删除队尾元素< / td >
< td > < span class = "arithmatex" > \(O(1)\)< / span > < / td >
< / tr >
< tr >
< td > peekFirst()< / td >
< td > 访问队首元素< / td >
< td > < span class = "arithmatex" > \(O(1)\)< / span > < / td >
< / tr >
< tr >
< td > peekLast()< / td >
< td > 访问队尾元素< / td >
< td > < span class = "arithmatex" > \(O(1)\)< / span > < / td >
< / tr >
< tr >
< td > size()< / td >
< td > 获取队列的长度< / td >
< td > < span class = "arithmatex" > \(O(1)\)< / span > < / td >
< / tr >
< tr >
< td > isEmpty()< / td >
< td > 判断队列是否为空< / td >
< td > < span class = "arithmatex" > \(O(1)\)< / span > < / td >
< / tr >
< / tbody >
< / table >
< / div >
< p > 相同地，我们可以直接使用编程语言实现好的双向队列类。< / p >
< div class = "tabbed-set tabbed-alternate" data-tabs = "1:10" > < input checked = "checked" id = "__tabbed_1_1" name = "__tabbed_1" type = "radio" / > < input id = "__tabbed_1_2" name = "__tabbed_1" type = "radio" / > < input id = "__tabbed_1_3" name = "__tabbed_1" type = "radio" / > < input id = "__tabbed_1_4" name = "__tabbed_1" type = "radio" / > < input id = "__tabbed_1_5" name = "__tabbed_1" type = "radio" / > < input id = "__tabbed_1_6" name = "__tabbed_1" type = "radio" / > < input id = "__tabbed_1_7" name = "__tabbed_1" type = "radio" / > < input id = "__tabbed_1_8" name = "__tabbed_1" type = "radio" / > < input id = "__tabbed_1_9" name = "__tabbed_1" type = "radio" / > < input id = "__tabbed_1_10" name = "__tabbed_1" type = "radio" / > < div class = "tabbed-labels" > < label for = "__tabbed_1_1" > Java< / label > < label for = "__tabbed_1_2" > C++< / label > < label for = "__tabbed_1_3" > Python< / label > < label for = "__tabbed_1_4" > Go< / label > < label for = "__tabbed_1_5" > JavaScript< / label > < label for = "__tabbed_1_6" > TypeScript< / label > < label for = "__tabbed_1_7" > C< / label > < label for = "__tabbed_1_8" > C#< / label > < label for = "__tabbed_1_9" > Swift< / label > < label for = "__tabbed_1_10" > Zig< / label > < / div >
< div class = "tabbed-content" >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > deque.java< / span > < pre > < span > < / span > < code > < a id = "__codelineno-0-1" name = "__codelineno-0-1" href = "#__codelineno-0-1" > < / a > < span class = "cm" > /* 初始化双向队列 */< / span >
< a id = "__codelineno-0-2" name = "__codelineno-0-2" href = "#__codelineno-0-2" > < / a > < span class = "n" > Deque< / span > < span class = "o" > < < / span > < span class = "n" > Integer< / span > < span class = "o" > > < / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > new< / span > < span class = "w" > < / span > < span class = "n" > LinkedList< / span > < span class = "o" > < > < / span > < span class = "p" > ();< / span >
< a id = "__codelineno-0-3" name = "__codelineno-0-3" href = "#__codelineno-0-3" > < / a >
< a id = "__codelineno-0-4" name = "__codelineno-0-4" href = "#__codelineno-0-4" > < / a > < span class = "cm" > /* 元素入队 */< / span >
< a id = "__codelineno-0-5" name = "__codelineno-0-5" href = "#__codelineno-0-5" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "na" > offerLast< / span > < span class = "p" > (< / span > < span class = "mi" > 2< / span > < span class = "p" > );< / span > < span class = "w" > < / span > < span class = "c1" > // 添加至队尾< / span >
< a id = "__codelineno-0-6" name = "__codelineno-0-6" href = "#__codelineno-0-6" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "na" > offerLast< / span > < span class = "p" > (< / span > < span class = "mi" > 5< / span > < span class = "p" > );< / span >
< a id = "__codelineno-0-7" name = "__codelineno-0-7" href = "#__codelineno-0-7" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "na" > offerLast< / span > < span class = "p" > (< / span > < span class = "mi" > 4< / span > < span class = "p" > );< / span >
< a id = "__codelineno-0-8" name = "__codelineno-0-8" href = "#__codelineno-0-8" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "na" > offerFirst< / span > < span class = "p" > (< / span > < span class = "mi" > 3< / span > < span class = "p" > );< / span > < span class = "w" > < / span > < span class = "c1" > // 添加至队首< / span >
< a id = "__codelineno-0-9" name = "__codelineno-0-9" href = "#__codelineno-0-9" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "na" > offerFirst< / span > < span class = "p" > (< / span > < span class = "mi" > 1< / span > < span class = "p" > );< / span >
< a id = "__codelineno-0-10" name = "__codelineno-0-10" href = "#__codelineno-0-10" > < / a >
< a id = "__codelineno-0-11" name = "__codelineno-0-11" href = "#__codelineno-0-11" > < / a > < span class = "cm" > /* 访问元素 */< / span >
< a id = "__codelineno-0-12" name = "__codelineno-0-12" href = "#__codelineno-0-12" > < / a > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > peekFirst< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "na" > peekFirst< / span > < span class = "p" > ();< / span > < span class = "w" > < / span > < span class = "c1" > // 队首元素< / span >
< a id = "__codelineno-0-13" name = "__codelineno-0-13" href = "#__codelineno-0-13" > < / a > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > peekLast< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "na" > peekLast< / span > < span class = "p" > ();< / span > < span class = "w" > < / span > < span class = "c1" > // 队尾元素< / span >
< a id = "__codelineno-0-14" name = "__codelineno-0-14" href = "#__codelineno-0-14" > < / a >
< a id = "__codelineno-0-15" name = "__codelineno-0-15" href = "#__codelineno-0-15" > < / a > < span class = "cm" > /* 元素出队 */< / span >
< a id = "__codelineno-0-16" name = "__codelineno-0-16" href = "#__codelineno-0-16" > < / a > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > pollFirst< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "na" > pollFirst< / span > < span class = "p" > ();< / span > < span class = "w" > < / span > < span class = "c1" > // 队首元素出队< / span >
< a id = "__codelineno-0-17" name = "__codelineno-0-17" href = "#__codelineno-0-17" > < / a > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > pollLast< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "na" > pollLast< / span > < span class = "p" > ();< / span > < span class = "w" > < / span > < span class = "c1" > // 队尾元素出队< / span >
< a id = "__codelineno-0-18" name = "__codelineno-0-18" href = "#__codelineno-0-18" > < / a >
< a id = "__codelineno-0-19" name = "__codelineno-0-19" href = "#__codelineno-0-19" > < / a > < span class = "cm" > /* 获取双向队列的长度 */< / span >
< a id = "__codelineno-0-20" name = "__codelineno-0-20" href = "#__codelineno-0-20" > < / a > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > size< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "na" > size< / span > < span class = "p" > ();< / span >
< a id = "__codelineno-0-21" name = "__codelineno-0-21" href = "#__codelineno-0-21" > < / a >
< a id = "__codelineno-0-22" name = "__codelineno-0-22" href = "#__codelineno-0-22" > < / a > < span class = "cm" > /* 判断双向队列是否为空 */< / span >
< a id = "__codelineno-0-23" name = "__codelineno-0-23" href = "#__codelineno-0-23" > < / a > < span class = "kt" > boolean< / span > < span class = "w" > < / span > < span class = "n" > isEmpty< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "na" > isEmpty< / span > < span class = "p" > ();< / span >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > deque.cpp< / span > < pre > < span > < / span > < code > < a id = "__codelineno-1-1" name = "__codelineno-1-1" href = "#__codelineno-1-1" > < / a > < span class = "cm" > /* 初始化双向队列 */< / span >
< a id = "__codelineno-1-2" name = "__codelineno-1-2" href = "#__codelineno-1-2" > < / a > < span class = "n" > deque< / span > < span class = "o" > < < / span > < span class = "kt" > int< / span > < span class = "o" > > < / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-1-3" name = "__codelineno-1-3" href = "#__codelineno-1-3" > < / a >
< a id = "__codelineno-1-4" name = "__codelineno-1-4" href = "#__codelineno-1-4" > < / a > < span class = "cm" > /* 元素入队 */< / span >
< a id = "__codelineno-1-5" name = "__codelineno-1-5" href = "#__codelineno-1-5" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > push_back< / span > < span class = "p" > (< / span > < span class = "mi" > 2< / span > < span class = "p" > );< / span > < span class = "w" > < / span > < span class = "c1" > // 添加至队尾< / span >
< a id = "__codelineno-1-6" name = "__codelineno-1-6" href = "#__codelineno-1-6" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > push_back< / span > < span class = "p" > (< / span > < span class = "mi" > 5< / span > < span class = "p" > );< / span >
< a id = "__codelineno-1-7" name = "__codelineno-1-7" href = "#__codelineno-1-7" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > push_back< / span > < span class = "p" > (< / span > < span class = "mi" > 4< / span > < span class = "p" > );< / span >
< a id = "__codelineno-1-8" name = "__codelineno-1-8" href = "#__codelineno-1-8" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > push_front< / span > < span class = "p" > (< / span > < span class = "mi" > 3< / span > < span class = "p" > );< / span > < span class = "w" > < / span > < span class = "c1" > // 添加至队首< / span >
< a id = "__codelineno-1-9" name = "__codelineno-1-9" href = "#__codelineno-1-9" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > push_front< / span > < span class = "p" > (< / span > < span class = "mi" > 1< / span > < span class = "p" > );< / span >
< a id = "__codelineno-1-10" name = "__codelineno-1-10" href = "#__codelineno-1-10" > < / a >
< a id = "__codelineno-1-11" name = "__codelineno-1-11" href = "#__codelineno-1-11" > < / a > < span class = "cm" > /* 访问元素 */< / span >
< a id = "__codelineno-1-12" name = "__codelineno-1-12" href = "#__codelineno-1-12" > < / a > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > front< / span > < span class = "p" > ();< / span > < span class = "w" > < / span > < span class = "c1" > // 队首元素< / span >
< a id = "__codelineno-1-13" name = "__codelineno-1-13" href = "#__codelineno-1-13" > < / a > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > back< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > back< / span > < span class = "p" > ();< / span > < span class = "w" > < / span > < span class = "c1" > // 队尾元素< / span >
< a id = "__codelineno-1-14" name = "__codelineno-1-14" href = "#__codelineno-1-14" > < / a >
< a id = "__codelineno-1-15" name = "__codelineno-1-15" href = "#__codelineno-1-15" > < / a > < span class = "cm" > /* 元素出队 */< / span >
< a id = "__codelineno-1-16" name = "__codelineno-1-16" href = "#__codelineno-1-16" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > pop_front< / span > < span class = "p" > ();< / span > < span class = "w" > < / span > < span class = "c1" > // 队首元素出队< / span >
< a id = "__codelineno-1-17" name = "__codelineno-1-17" href = "#__codelineno-1-17" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > pop_back< / span > < span class = "p" > ();< / span > < span class = "w" > < / span > < span class = "c1" > // 队尾元素出队< / span >
< a id = "__codelineno-1-18" name = "__codelineno-1-18" href = "#__codelineno-1-18" > < / a >
< a id = "__codelineno-1-19" name = "__codelineno-1-19" href = "#__codelineno-1-19" > < / a > < span class = "cm" > /* 获取双向队列的长度 */< / span >
< a id = "__codelineno-1-20" name = "__codelineno-1-20" href = "#__codelineno-1-20" > < / a > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > size< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > size< / span > < span class = "p" > ();< / span >
< a id = "__codelineno-1-21" name = "__codelineno-1-21" href = "#__codelineno-1-21" > < / a >
< a id = "__codelineno-1-22" name = "__codelineno-1-22" href = "#__codelineno-1-22" > < / a > < span class = "cm" > /* 判断双向队列是否为空 */< / span >
< a id = "__codelineno-1-23" name = "__codelineno-1-23" href = "#__codelineno-1-23" > < / a > < span class = "kt" > bool< / span > < span class = "w" > < / span > < span class = "n" > empty< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > empty< / span > < span class = "p" > ();< / span >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > deque.py< / span > < pre > < span > < / span > < code > < a id = "__codelineno-2-1" name = "__codelineno-2-1" href = "#__codelineno-2-1" > < / a > < span class = "sd" > " " " 初始化双向队列 " " " < / span >
< a id = "__codelineno-2-2" name = "__codelineno-2-2" href = "#__codelineno-2-2" > < / a > < span class = "n" > duque< / span > < span class = "o" > =< / span > < span class = "n" > deque< / span > < span class = "p" > ()< / span >
< a id = "__codelineno-2-3" name = "__codelineno-2-3" href = "#__codelineno-2-3" > < / a >
< a id = "__codelineno-2-4" name = "__codelineno-2-4" href = "#__codelineno-2-4" > < / a > < span class = "sd" > " " " 元素入队 " " " < / span >
< a id = "__codelineno-2-5" name = "__codelineno-2-5" href = "#__codelineno-2-5" > < / a > < span class = "n" > duque< / span > < span class = "o" > .< / span > < span class = "n" > append< / span > < span class = "p" > (< / span > < span class = "mi" > 2< / span > < span class = "p" > )< / span > < span class = "c1" > # 添加至队尾< / span >
< a id = "__codelineno-2-6" name = "__codelineno-2-6" href = "#__codelineno-2-6" > < / a > < span class = "n" > duque< / span > < span class = "o" > .< / span > < span class = "n" > append< / span > < span class = "p" > (< / span > < span class = "mi" > 5< / span > < span class = "p" > )< / span >
< a id = "__codelineno-2-7" name = "__codelineno-2-7" href = "#__codelineno-2-7" > < / a > < span class = "n" > duque< / span > < span class = "o" > .< / span > < span class = "n" > append< / span > < span class = "p" > (< / span > < span class = "mi" > 4< / span > < span class = "p" > )< / span >
< a id = "__codelineno-2-8" name = "__codelineno-2-8" href = "#__codelineno-2-8" > < / a > < span class = "n" > duque< / span > < span class = "o" > .< / span > < span class = "n" > appendleft< / span > < span class = "p" > (< / span > < span class = "mi" > 3< / span > < span class = "p" > )< / span > < span class = "c1" > # 添加至队首< / span >
< a id = "__codelineno-2-9" name = "__codelineno-2-9" href = "#__codelineno-2-9" > < / a > < span class = "n" > duque< / span > < span class = "o" > .< / span > < span class = "n" > appendleft< / span > < span class = "p" > (< / span > < span class = "mi" > 1< / span > < span class = "p" > )< / span >
< a id = "__codelineno-2-10" name = "__codelineno-2-10" href = "#__codelineno-2-10" > < / a >
< a id = "__codelineno-2-11" name = "__codelineno-2-11" href = "#__codelineno-2-11" > < / a > < span class = "sd" > " " " 访问元素 " " " < / span >
< a id = "__codelineno-2-12" name = "__codelineno-2-12" href = "#__codelineno-2-12" > < / a > < span class = "n" > front< / span > < span class = "o" > =< / span > < span class = "n" > duque< / span > < span class = "p" > [< / span > < span class = "mi" > 0< / span > < span class = "p" > ]< / span > < span class = "c1" > # 队首元素< / span >
< a id = "__codelineno-2-13" name = "__codelineno-2-13" href = "#__codelineno-2-13" > < / a > < span class = "n" > rear< / span > < span class = "o" > =< / span > < span class = "n" > duque< / span > < span class = "p" > [< / span > < span class = "o" > -< / span > < span class = "mi" > 1< / span > < span class = "p" > ]< / span > < span class = "c1" > # 队尾元素< / span >
< a id = "__codelineno-2-14" name = "__codelineno-2-14" href = "#__codelineno-2-14" > < / a >
< a id = "__codelineno-2-15" name = "__codelineno-2-15" href = "#__codelineno-2-15" > < / a > < span class = "sd" > " " " 元素出队 " " " < / span >
< a id = "__codelineno-2-16" name = "__codelineno-2-16" href = "#__codelineno-2-16" > < / a > < span class = "n" > pop_front< / span > < span class = "o" > =< / span > < span class = "n" > duque< / span > < span class = "o" > .< / span > < span class = "n" > popleft< / span > < span class = "p" > ()< / span > < span class = "c1" > # 队首元素出队< / span >
< a id = "__codelineno-2-17" name = "__codelineno-2-17" href = "#__codelineno-2-17" > < / a > < span class = "n" > pop_rear< / span > < span class = "o" > =< / span > < span class = "n" > duque< / span > < span class = "o" > .< / span > < span class = "n" > pop< / span > < span class = "p" > ()< / span > < span class = "c1" > # 队尾元素出队< / span >
< a id = "__codelineno-2-18" name = "__codelineno-2-18" href = "#__codelineno-2-18" > < / a >
< a id = "__codelineno-2-19" name = "__codelineno-2-19" href = "#__codelineno-2-19" > < / a > < span class = "sd" > " " " 获取双向队列的长度 " " " < / span >
< a id = "__codelineno-2-20" name = "__codelineno-2-20" href = "#__codelineno-2-20" > < / a > < span class = "n" > size< / span > < span class = "o" > =< / span > < span class = "nb" > len< / span > < span class = "p" > (< / span > < span class = "n" > duque< / span > < span class = "p" > )< / span >
< a id = "__codelineno-2-21" name = "__codelineno-2-21" href = "#__codelineno-2-21" > < / a >
< a id = "__codelineno-2-22" name = "__codelineno-2-22" href = "#__codelineno-2-22" > < / a > < span class = "sd" > " " " 判断双向队列是否为空 " " " < / span >
< a id = "__codelineno-2-23" name = "__codelineno-2-23" href = "#__codelineno-2-23" > < / a > < span class = "n" > is_empty< / span > < span class = "o" > =< / span > < span class = "nb" > len< / span > < span class = "p" > (< / span > < span class = "n" > duque< / span > < span class = "p" > )< / span > < span class = "o" > ==< / span > < span class = "mi" > 0< / span >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > deque_test.go< / span > < pre > < span > < / span > < code > < a id = "__codelineno-3-1" name = "__codelineno-3-1" href = "#__codelineno-3-1" > < / a > < span class = "cm" > /* 初始化双向队列 */< / span >
< a id = "__codelineno-3-2" name = "__codelineno-3-2" href = "#__codelineno-3-2" > < / a > < span class = "c1" > // 在 Go 中，将 list 作为双向队列使用< / span >
< a id = "__codelineno-3-3" name = "__codelineno-3-3" href = "#__codelineno-3-3" > < / a > < span class = "nx" > deque< / span > < span class = "w" > < / span > < span class = "o" > :=< / span > < span class = "w" > < / span > < span class = "nx" > list< / span > < span class = "p" > .< / span > < span class = "nx" > New< / span > < span class = "p" > ()< / span >
< a id = "__codelineno-3-4" name = "__codelineno-3-4" href = "#__codelineno-3-4" > < / a >
< a id = "__codelineno-3-5" name = "__codelineno-3-5" href = "#__codelineno-3-5" > < / a > < span class = "cm" > /* 元素入队 */< / span >
< a id = "__codelineno-3-6" name = "__codelineno-3-6" href = "#__codelineno-3-6" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > PushBack< / span > < span class = "p" > (< / span > < span class = "mi" > 2< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "c1" > // 添加至队尾< / span >
< a id = "__codelineno-3-7" name = "__codelineno-3-7" href = "#__codelineno-3-7" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > PushBack< / span > < span class = "p" > (< / span > < span class = "mi" > 5< / span > < span class = "p" > )< / span >
< a id = "__codelineno-3-8" name = "__codelineno-3-8" href = "#__codelineno-3-8" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > PushBack< / span > < span class = "p" > (< / span > < span class = "mi" > 4< / span > < span class = "p" > )< / span >
< a id = "__codelineno-3-9" name = "__codelineno-3-9" href = "#__codelineno-3-9" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > PushFront< / span > < span class = "p" > (< / span > < span class = "mi" > 3< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "c1" > // 添加至队首< / span >
< a id = "__codelineno-3-10" name = "__codelineno-3-10" href = "#__codelineno-3-10" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > PushFront< / span > < span class = "p" > (< / span > < span class = "mi" > 1< / span > < span class = "p" > )< / span >
< a id = "__codelineno-3-11" name = "__codelineno-3-11" href = "#__codelineno-3-11" > < / a >
< a id = "__codelineno-3-12" name = "__codelineno-3-12" href = "#__codelineno-3-12" > < / a > < span class = "cm" > /* 访问元素 */< / span >
< a id = "__codelineno-3-13" name = "__codelineno-3-13" href = "#__codelineno-3-13" > < / a > < span class = "nx" > front< / span > < span class = "w" > < / span > < span class = "o" > :=< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > Front< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "c1" > // 队首元素< / span >
< a id = "__codelineno-3-14" name = "__codelineno-3-14" href = "#__codelineno-3-14" > < / a > < span class = "nx" > rear< / span > < span class = "w" > < / span > < span class = "o" > :=< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > Back< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "c1" > // 队尾元素< / span >
< a id = "__codelineno-3-15" name = "__codelineno-3-15" href = "#__codelineno-3-15" > < / a >
< a id = "__codelineno-3-16" name = "__codelineno-3-16" href = "#__codelineno-3-16" > < / a > < span class = "cm" > /* 元素出队 */< / span >
< a id = "__codelineno-3-17" name = "__codelineno-3-17" href = "#__codelineno-3-17" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > Remove< / span > < span class = "p" > (< / span > < span class = "nx" > front< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "c1" > // 队首元素出队< / span >
< a id = "__codelineno-3-18" name = "__codelineno-3-18" href = "#__codelineno-3-18" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > Remove< / span > < span class = "p" > (< / span > < span class = "nx" > rear< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "c1" > // 队尾元素出队< / span >
< a id = "__codelineno-3-19" name = "__codelineno-3-19" href = "#__codelineno-3-19" > < / a >
< a id = "__codelineno-3-20" name = "__codelineno-3-20" href = "#__codelineno-3-20" > < / a > < span class = "cm" > /* 获取双向队列的长度 */< / span >
< a id = "__codelineno-3-21" name = "__codelineno-3-21" href = "#__codelineno-3-21" > < / a > < span class = "nx" > size< / span > < span class = "w" > < / span > < span class = "o" > :=< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > Len< / span > < span class = "p" > ()< / span >
< a id = "__codelineno-3-22" name = "__codelineno-3-22" href = "#__codelineno-3-22" > < / a >
< a id = "__codelineno-3-23" name = "__codelineno-3-23" href = "#__codelineno-3-23" > < / a > < span class = "cm" > /* 判断双向队列是否为空 */< / span >
< a id = "__codelineno-3-24" name = "__codelineno-3-24" href = "#__codelineno-3-24" > < / a > < span class = "nx" > isEmpty< / span > < span class = "w" > < / span > < span class = "o" > :=< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > Len< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "o" > ==< / span > < span class = "w" > < / span > < span class = "mi" > 0< / span >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > deque.js< / span > < pre > < span > < / span > < code > < a id = "__codelineno-4-1" name = "__codelineno-4-1" href = "#__codelineno-4-1" > < / a > < span class = "cm" > /* 初始化双向队列 */< / span >
< a id = "__codelineno-4-2" name = "__codelineno-4-2" href = "#__codelineno-4-2" > < / a > < span class = "c1" > // JavaScript 没有内置的双端队列，只能把 Array 当作双端队列来使用< / span >
< a id = "__codelineno-4-3" name = "__codelineno-4-3" href = "#__codelineno-4-3" > < / a > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "p" > [];< / span >
< a id = "__codelineno-4-4" name = "__codelineno-4-4" href = "#__codelineno-4-4" > < / a >
< a id = "__codelineno-4-5" name = "__codelineno-4-5" href = "#__codelineno-4-5" > < / a > < span class = "cm" > /* 元素入队 */< / span >
< a id = "__codelineno-4-6" name = "__codelineno-4-6" href = "#__codelineno-4-6" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > push< / span > < span class = "p" > (< / span > < span class = "mf" > 2< / span > < span class = "p" > );< / span >
< a id = "__codelineno-4-7" name = "__codelineno-4-7" href = "#__codelineno-4-7" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > push< / span > < span class = "p" > (< / span > < span class = "mf" > 5< / span > < span class = "p" > );< / span >
< a id = "__codelineno-4-8" name = "__codelineno-4-8" href = "#__codelineno-4-8" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > push< / span > < span class = "p" > (< / span > < span class = "mf" > 4< / span > < span class = "p" > );< / span >
< a id = "__codelineno-4-9" name = "__codelineno-4-9" href = "#__codelineno-4-9" > < / a > < span class = "c1" > // 请注意， ， < / span >
< a id = "__codelineno-4-10" name = "__codelineno-4-10" href = "#__codelineno-4-10" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > unshift< / span > < span class = "p" > (< / span > < span class = "mf" > 3< / span > < span class = "p" > );< / span >
< a id = "__codelineno-4-11" name = "__codelineno-4-11" href = "#__codelineno-4-11" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > unshift< / span > < span class = "p" > (< / span > < span class = "mf" > 1< / span > < span class = "p" > );< / span >
< a id = "__codelineno-4-12" name = "__codelineno-4-12" href = "#__codelineno-4-12" > < / a > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " 双向队列 deque = " < / span > < span class = "p" > ,< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > );< / span >
< a id = "__codelineno-4-13" name = "__codelineno-4-13" href = "#__codelineno-4-13" > < / a >
< a id = "__codelineno-4-14" name = "__codelineno-4-14" href = "#__codelineno-4-14" > < / a > < span class = "cm" > /* 访问元素 */< / span >
< a id = "__codelineno-4-15" name = "__codelineno-4-15" href = "#__codelineno-4-15" > < / a > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > peekFirst< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > [< / span > < span class = "mf" > 0< / span > < span class = "p" > ];< / span >
< a id = "__codelineno-4-16" name = "__codelineno-4-16" href = "#__codelineno-4-16" > < / a > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " 队首元素 peekFirst = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > peekFirst< / span > < span class = "p" > );< / span >
< a id = "__codelineno-4-17" name = "__codelineno-4-17" href = "#__codelineno-4-17" > < / a > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > peekLast< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > [< / span > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > length< / span > < span class = "w" > < / span > < span class = "o" > -< / span > < span class = "w" > < / span > < span class = "mf" > 1< / span > < span class = "p" > ];< / span >
< a id = "__codelineno-4-18" name = "__codelineno-4-18" href = "#__codelineno-4-18" > < / a > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " 队尾元素 peekLast = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > peekLast< / span > < span class = "p" > );< / span >
< a id = "__codelineno-4-19" name = "__codelineno-4-19" href = "#__codelineno-4-19" > < / a >
< a id = "__codelineno-4-20" name = "__codelineno-4-20" href = "#__codelineno-4-20" > < / a > < span class = "cm" > /* 元素出队 */< / span >
< a id = "__codelineno-4-21" name = "__codelineno-4-21" href = "#__codelineno-4-21" > < / a > < span class = "c1" > // 请注意， ， < / span >
< a id = "__codelineno-4-22" name = "__codelineno-4-22" href = "#__codelineno-4-22" > < / a > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > popFront< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > shift< / span > < span class = "p" > ();< / span >
< a id = "__codelineno-4-23" name = "__codelineno-4-23" href = "#__codelineno-4-23" > < / a > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " 队首出队元素 popFront = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > popFront< / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "s2" > " ，队首出队后 deque = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > );< / span >
< a id = "__codelineno-4-24" name = "__codelineno-4-24" href = "#__codelineno-4-24" > < / a > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > popBack< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > pop< / span > < span class = "p" > ();< / span >
< a id = "__codelineno-4-25" name = "__codelineno-4-25" href = "#__codelineno-4-25" > < / a > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " 队尾出队元素 popBack = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > popBack< / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "s2" > " ，队尾出队后 deque = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > );< / span >
< a id = "__codelineno-4-26" name = "__codelineno-4-26" href = "#__codelineno-4-26" > < / a >
< a id = "__codelineno-4-27" name = "__codelineno-4-27" href = "#__codelineno-4-27" > < / a > < span class = "cm" > /* 获取双向队列的长度 */< / span >
< a id = "__codelineno-4-28" name = "__codelineno-4-28" href = "#__codelineno-4-28" > < / a > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > size< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > length< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-4-29" name = "__codelineno-4-29" href = "#__codelineno-4-29" > < / a > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " 双向队列长度 size = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > size< / span > < span class = "p" > );< / span >
< a id = "__codelineno-4-30" name = "__codelineno-4-30" href = "#__codelineno-4-30" > < / a >
< a id = "__codelineno-4-31" name = "__codelineno-4-31" href = "#__codelineno-4-31" > < / a > < span class = "cm" > /* 判断双向队列是否为空 */< / span >
< a id = "__codelineno-4-32" name = "__codelineno-4-32" href = "#__codelineno-4-32" > < / a > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > isEmpty< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > size< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-4-33" name = "__codelineno-4-33" href = "#__codelineno-4-33" > < / a > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " 双向队列是否为空 = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > isEmpty< / span > < span class = "p" > );< / span >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > deque.ts< / span > < pre > < span > < / span > < code > < a id = "__codelineno-5-1" name = "__codelineno-5-1" href = "#__codelineno-5-1" > < / a > < span class = "cm" > /* 初始化双向队列 */< / span >
< a id = "__codelineno-5-2" name = "__codelineno-5-2" href = "#__codelineno-5-2" > < / a > < span class = "c1" > // TypeScript 没有内置的双端队列，只能把 Array 当作双端队列来使用< / span >
< a id = "__codelineno-5-3" name = "__codelineno-5-3" href = "#__codelineno-5-3" > < / a > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "p" > []< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "p" > [];< / span >
< a id = "__codelineno-5-4" name = "__codelineno-5-4" href = "#__codelineno-5-4" > < / a >
< a id = "__codelineno-5-5" name = "__codelineno-5-5" href = "#__codelineno-5-5" > < / a > < span class = "cm" > /* 元素入队 */< / span >
< a id = "__codelineno-5-6" name = "__codelineno-5-6" href = "#__codelineno-5-6" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > push< / span > < span class = "p" > (< / span > < span class = "mf" > 2< / span > < span class = "p" > );< / span >
< a id = "__codelineno-5-7" name = "__codelineno-5-7" href = "#__codelineno-5-7" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > push< / span > < span class = "p" > (< / span > < span class = "mf" > 5< / span > < span class = "p" > );< / span >
< a id = "__codelineno-5-8" name = "__codelineno-5-8" href = "#__codelineno-5-8" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > push< / span > < span class = "p" > (< / span > < span class = "mf" > 4< / span > < span class = "p" > );< / span >
< a id = "__codelineno-5-9" name = "__codelineno-5-9" href = "#__codelineno-5-9" > < / a > < span class = "c1" > // 请注意， ， < / span >
< a id = "__codelineno-5-10" name = "__codelineno-5-10" href = "#__codelineno-5-10" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > unshift< / span > < span class = "p" > (< / span > < span class = "mf" > 3< / span > < span class = "p" > );< / span >
< a id = "__codelineno-5-11" name = "__codelineno-5-11" href = "#__codelineno-5-11" > < / a > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > unshift< / span > < span class = "p" > (< / span > < span class = "mf" > 1< / span > < span class = "p" > );< / span >
< a id = "__codelineno-5-12" name = "__codelineno-5-12" href = "#__codelineno-5-12" > < / a > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " 双向队列 deque = " < / span > < span class = "p" > ,< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > );< / span >
< a id = "__codelineno-5-13" name = "__codelineno-5-13" href = "#__codelineno-5-13" > < / a >
< a id = "__codelineno-5-14" name = "__codelineno-5-14" href = "#__codelineno-5-14" > < / a > < span class = "cm" > /* 访问元素 */< / span >
< a id = "__codelineno-5-15" name = "__codelineno-5-15" href = "#__codelineno-5-15" > < / a > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > peekFirst< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > [< / span > < span class = "mf" > 0< / span > < span class = "p" > ];< / span >
< a id = "__codelineno-5-16" name = "__codelineno-5-16" href = "#__codelineno-5-16" > < / a > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " 队首元素 peekFirst = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > peekFirst< / span > < span class = "p" > );< / span >
< a id = "__codelineno-5-17" name = "__codelineno-5-17" href = "#__codelineno-5-17" > < / a > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > peekLast< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > [< / span > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > length< / span > < span class = "w" > < / span > < span class = "o" > -< / span > < span class = "w" > < / span > < span class = "mf" > 1< / span > < span class = "p" > ];< / span >
< a id = "__codelineno-5-18" name = "__codelineno-5-18" href = "#__codelineno-5-18" > < / a > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " 队尾元素 peekLast = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > peekLast< / span > < span class = "p" > );< / span >
< a id = "__codelineno-5-19" name = "__codelineno-5-19" href = "#__codelineno-5-19" > < / a >
< a id = "__codelineno-5-20" name = "__codelineno-5-20" href = "#__codelineno-5-20" > < / a > < span class = "cm" > /* 元素出队 */< / span >
< a id = "__codelineno-5-21" name = "__codelineno-5-21" href = "#__codelineno-5-21" > < / a > < span class = "c1" > // 请注意， ， < / span >
< a id = "__codelineno-5-22" name = "__codelineno-5-22" href = "#__codelineno-5-22" > < / a > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > popFront< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > shift< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "kr" > as< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-5-23" name = "__codelineno-5-23" href = "#__codelineno-5-23" > < / a > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " 队首出队元素 popFront = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > popFront< / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "s2" > " ，队首出队后 deque = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > );< / span >
< a id = "__codelineno-5-24" name = "__codelineno-5-24" href = "#__codelineno-5-24" > < / a > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > popBack< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > pop< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "kr" > as< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-5-25" name = "__codelineno-5-25" href = "#__codelineno-5-25" > < / a > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " 队尾出队元素 popBack = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > popBack< / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "s2" > " ，队尾出队后 deque = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > );< / span >
< a id = "__codelineno-5-26" name = "__codelineno-5-26" href = "#__codelineno-5-26" > < / a >
< a id = "__codelineno-5-27" name = "__codelineno-5-27" href = "#__codelineno-5-27" > < / a > < span class = "cm" > /* 获取双向队列的长度 */< / span >
< a id = "__codelineno-5-28" name = "__codelineno-5-28" href = "#__codelineno-5-28" > < / a > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > size< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > deque< / span > < span class = "p" > .< / span > < span class = "nx" > length< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-5-29" name = "__codelineno-5-29" href = "#__codelineno-5-29" > < / a > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " 双向队列长度 size = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > size< / span > < span class = "p" > );< / span >
< a id = "__codelineno-5-30" name = "__codelineno-5-30" href = "#__codelineno-5-30" > < / a >
< a id = "__codelineno-5-31" name = "__codelineno-5-31" href = "#__codelineno-5-31" > < / a > < span class = "cm" > /* 判断双向队列是否为空 */< / span >
< a id = "__codelineno-5-32" name = "__codelineno-5-32" href = "#__codelineno-5-32" > < / a > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > isEmpty< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > boolean< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > size< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-5-33" name = "__codelineno-5-33" href = "#__codelineno-5-33" > < / a > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " 双向队列是否为空 = " < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > isEmpty< / span > < span class = "p" > );< / span >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > deque.c< / span > < pre > < span > < / span > < code > < a id = "__codelineno-6-1" name = "__codelineno-6-1" href = "#__codelineno-6-1" > < / a >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > deque.cs< / span > < pre > < span > < / span > < code > < a id = "__codelineno-7-1" name = "__codelineno-7-1" href = "#__codelineno-7-1" > < / a > < span class = "cm" > /* 初始化双向队列 */< / span >
< a id = "__codelineno-7-2" name = "__codelineno-7-2" href = "#__codelineno-7-2" > < / a > < span class = "c1" > // 在 C# 中，将链表 LinkedList 看作双向队列来使用< / span >
< a id = "__codelineno-7-3" name = "__codelineno-7-3" href = "#__codelineno-7-3" > < / a > < span class = "n" > LinkedList< / span > < span class = "o" > < < / span > < span class = "kt" > int< / span > < span class = "o" > > < / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > new< / span > < span class = "w" > < / span > < span class = "n" > LinkedList< / span > < span class = "o" > < < / span > < span class = "kt" > int< / span > < span class = "o" > > < / span > < span class = "p" > ();< / span >
< a id = "__codelineno-7-4" name = "__codelineno-7-4" href = "#__codelineno-7-4" > < / a >
< a id = "__codelineno-7-5" name = "__codelineno-7-5" href = "#__codelineno-7-5" > < / a > < span class = "cm" > /* 元素入队 */< / span >
< a id = "__codelineno-7-6" name = "__codelineno-7-6" href = "#__codelineno-7-6" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > AddLast< / span > < span class = "p" > (< / span > < span class = "m" > 2< / span > < span class = "p" > );< / span > < span class = "w" > < / span > < span class = "c1" > // 添加至队尾< / span >
< a id = "__codelineno-7-7" name = "__codelineno-7-7" href = "#__codelineno-7-7" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > AddLast< / span > < span class = "p" > (< / span > < span class = "m" > 5< / span > < span class = "p" > );< / span >
< a id = "__codelineno-7-8" name = "__codelineno-7-8" href = "#__codelineno-7-8" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > AddLast< / span > < span class = "p" > (< / span > < span class = "m" > 4< / span > < span class = "p" > );< / span >
< a id = "__codelineno-7-9" name = "__codelineno-7-9" href = "#__codelineno-7-9" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > AddFirst< / span > < span class = "p" > (< / span > < span class = "m" > 3< / span > < span class = "p" > );< / span > < span class = "w" > < / span > < span class = "c1" > // 添加至队首< / span >
< a id = "__codelineno-7-10" name = "__codelineno-7-10" href = "#__codelineno-7-10" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > AddFirst< / span > < span class = "p" > (< / span > < span class = "m" > 1< / span > < span class = "p" > );< / span >
< a id = "__codelineno-7-11" name = "__codelineno-7-11" href = "#__codelineno-7-11" > < / a >
< a id = "__codelineno-7-12" name = "__codelineno-7-12" href = "#__codelineno-7-12" > < / a > < span class = "cm" > /* 访问元素 */< / span >
< a id = "__codelineno-7-13" name = "__codelineno-7-13" href = "#__codelineno-7-13" > < / a > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > peekFirst< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > First< / span > < span class = "p" > .< / span > < span class = "n" > Value< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 队首元素< / span >
< a id = "__codelineno-7-14" name = "__codelineno-7-14" href = "#__codelineno-7-14" > < / a > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > peekLast< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > Last< / span > < span class = "p" > .< / span > < span class = "n" > Value< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 队尾元素< / span >
< a id = "__codelineno-7-15" name = "__codelineno-7-15" href = "#__codelineno-7-15" > < / a >
< a id = "__codelineno-7-16" name = "__codelineno-7-16" href = "#__codelineno-7-16" > < / a > < span class = "cm" > /* 元素出队 */< / span >
< a id = "__codelineno-7-17" name = "__codelineno-7-17" href = "#__codelineno-7-17" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > RemoveFirst< / span > < span class = "p" > ();< / span > < span class = "w" > < / span > < span class = "c1" > // 队首元素出队< / span >
< a id = "__codelineno-7-18" name = "__codelineno-7-18" href = "#__codelineno-7-18" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > RemoveLast< / span > < span class = "p" > ();< / span > < span class = "w" > < / span > < span class = "c1" > // 队尾元素出队< / span >
< a id = "__codelineno-7-19" name = "__codelineno-7-19" href = "#__codelineno-7-19" > < / a >
< a id = "__codelineno-7-20" name = "__codelineno-7-20" href = "#__codelineno-7-20" > < / a > < span class = "cm" > /* 获取双向队列的长度 */< / span >
< a id = "__codelineno-7-21" name = "__codelineno-7-21" href = "#__codelineno-7-21" > < / a > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > size< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > Count< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-7-22" name = "__codelineno-7-22" href = "#__codelineno-7-22" > < / a >
< a id = "__codelineno-7-23" name = "__codelineno-7-23" href = "#__codelineno-7-23" > < / a > < span class = "cm" > /* 判断双向队列是否为空 */< / span >
< a id = "__codelineno-7-24" name = "__codelineno-7-24" href = "#__codelineno-7-24" > < / a > < span class = "kt" > bool< / span > < span class = "w" > < / span > < span class = "n" > isEmpty< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > Count< / span > < span class = "w" > < / span > < span class = "o" > ==< / span > < span class = "w" > < / span > < span class = "m" > 0< / span > < span class = "p" > ;< / span >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > deque.swift< / span > < pre > < span > < / span > < code > < a id = "__codelineno-8-1" name = "__codelineno-8-1" href = "#__codelineno-8-1" > < / a > < span class = "cm" > /* 初始化双向队列 */< / span >
< a id = "__codelineno-8-2" name = "__codelineno-8-2" href = "#__codelineno-8-2" > < / a > < span class = "c1" > // Swift 没有内置的双向队列类，可以把 Array 当作双向队列来使用< / span >
< a id = "__codelineno-8-3" name = "__codelineno-8-3" href = "#__codelineno-8-3" > < / a > < span class = "kd" > var< / span > < span class = "nv" > deque< / span > < span class = "p" > :< / span > < span class = "p" > [< / span > < span class = "nb" > Int< / span > < span class = "p" > ]< / span > < span class = "p" > =< / span > < span class = "p" > []< / span >
< a id = "__codelineno-8-4" name = "__codelineno-8-4" href = "#__codelineno-8-4" > < / a >
< a id = "__codelineno-8-5" name = "__codelineno-8-5" href = "#__codelineno-8-5" > < / a > < span class = "cm" > /* 元素入队 */< / span >
< a id = "__codelineno-8-6" name = "__codelineno-8-6" href = "#__codelineno-8-6" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > append< / span > < span class = "p" > (< / span > < span class = "mi" > 2< / span > < span class = "p" > )< / span > < span class = "c1" > // 添加至队尾< / span >
< a id = "__codelineno-8-7" name = "__codelineno-8-7" href = "#__codelineno-8-7" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > append< / span > < span class = "p" > (< / span > < span class = "mi" > 5< / span > < span class = "p" > )< / span >
< a id = "__codelineno-8-8" name = "__codelineno-8-8" href = "#__codelineno-8-8" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > append< / span > < span class = "p" > (< / span > < span class = "mi" > 4< / span > < span class = "p" > )< / span >
< a id = "__codelineno-8-9" name = "__codelineno-8-9" href = "#__codelineno-8-9" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "bp" > insert< / span > < span class = "p" > (< / span > < span class = "mi" > 3< / span > < span class = "p" > ,< / span > < span class = "n" > at< / span > < span class = "p" > :< / span > < span class = "mi" > 0< / span > < span class = "p" > )< / span > < span class = "c1" > // 添加至队首< / span >
< a id = "__codelineno-8-10" name = "__codelineno-8-10" href = "#__codelineno-8-10" > < / a > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "bp" > insert< / span > < span class = "p" > (< / span > < span class = "mi" > 1< / span > < span class = "p" > ,< / span > < span class = "n" > at< / span > < span class = "p" > :< / span > < span class = "mi" > 0< / span > < span class = "p" > )< / span >
< a id = "__codelineno-8-11" name = "__codelineno-8-11" href = "#__codelineno-8-11" > < / a >
< a id = "__codelineno-8-12" name = "__codelineno-8-12" href = "#__codelineno-8-12" > < / a > < span class = "cm" > /* 访问元素 */< / span >
< a id = "__codelineno-8-13" name = "__codelineno-8-13" href = "#__codelineno-8-13" > < / a > < span class = "kd" > let< / span > < span class = "nv" > peekFirst< / span > < span class = "p" > =< / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "bp" > first< / span > < span class = "p" > !< / span > < span class = "c1" > // 队首元素< / span >
< a id = "__codelineno-8-14" name = "__codelineno-8-14" href = "#__codelineno-8-14" > < / a > < span class = "kd" > let< / span > < span class = "nv" > peekLast< / span > < span class = "p" > =< / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "bp" > last< / span > < span class = "p" > !< / span > < span class = "c1" > // 队尾元素< / span >
< a id = "__codelineno-8-15" name = "__codelineno-8-15" href = "#__codelineno-8-15" > < / a >
< a id = "__codelineno-8-16" name = "__codelineno-8-16" href = "#__codelineno-8-16" > < / a > < span class = "cm" > /* 元素出队 */< / span >
< a id = "__codelineno-8-17" name = "__codelineno-8-17" href = "#__codelineno-8-17" > < / a > < span class = "c1" > // 使用 Array 模拟时 pollFirst 的复杂度为 O(n)< / span >
< a id = "__codelineno-8-18" name = "__codelineno-8-18" href = "#__codelineno-8-18" > < / a > < span class = "kd" > let< / span > < span class = "nv" > pollFirst< / span > < span class = "p" > =< / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "n" > removeFirst< / span > < span class = "p" > ()< / span > < span class = "c1" > // 队首元素出队< / span >
< a id = "__codelineno-8-19" name = "__codelineno-8-19" href = "#__codelineno-8-19" > < / a > < span class = "kd" > let< / span > < span class = "nv" > pollLast< / span > < span class = "p" > =< / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "bp" > removeLast< / span > < span class = "p" > ()< / span > < span class = "c1" > // 队尾元素出队< / span >
< a id = "__codelineno-8-20" name = "__codelineno-8-20" href = "#__codelineno-8-20" > < / a >
< a id = "__codelineno-8-21" name = "__codelineno-8-21" href = "#__codelineno-8-21" > < / a > < span class = "cm" > /* 获取双向队列的长度 */< / span >
< a id = "__codelineno-8-22" name = "__codelineno-8-22" href = "#__codelineno-8-22" > < / a > < span class = "kd" > let< / span > < span class = "nv" > size< / span > < span class = "p" > =< / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "bp" > count< / span >
< a id = "__codelineno-8-23" name = "__codelineno-8-23" href = "#__codelineno-8-23" > < / a >
< a id = "__codelineno-8-24" name = "__codelineno-8-24" href = "#__codelineno-8-24" > < / a > < span class = "cm" > /* 判断双向队列是否为空 */< / span >
< a id = "__codelineno-8-25" name = "__codelineno-8-25" href = "#__codelineno-8-25" > < / a > < span class = "kd" > let< / span > < span class = "nv" > isEmpty< / span > < span class = "p" > =< / span > < span class = "n" > deque< / span > < span class = "p" > .< / span > < span class = "bp" > isEmpty< / span >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > deque.zig< / span > < pre > < span > < / span > < code > < a id = "__codelineno-9-1" name = "__codelineno-9-1" href = "#__codelineno-9-1" > < / a >
< / code > < / pre > < / div >
< / div >
< / div >
< / div >
< h2 id = "532" > 5.3.2. 双向队列实现 *< a class = "headerlink" href = "#532" title = "Permanent link" > ¶ < / a > < / h2 >
< p > 与队列类似，双向队列同样可以使用链表或数组来实现。< / p >
< h3 id = "_1" > 基于双向链表的实现< a class = "headerlink" href = "#_1" title = "Permanent link" > ¶ < / a > < / h3 >
< p > 回忆上节内容，由于可以方便地删除链表头结点（对应出队操作），以及在链表尾结点后添加新结点（对应入队操作），因此我们使用普通单向链表来实现队列。< / p >
< p > 而双向队列的头部和尾部都可以执行入队与出队操作，换言之，双向队列的操作是“首尾对称”的，也需要实现另一个对称方向的操作。因此，双向队列需要使用「双向链表」来实现。< / p >
< p > 我们将双向链表的头结点和尾结点分别看作双向队列的队首和队尾，并且实现在两端都能添加与删除结点。< / p >
< div class = "tabbed-set tabbed-alternate" data-tabs = "2:5" > < input checked = "checked" id = "__tabbed_2_1" name = "__tabbed_2" type = "radio" / > < input id = "__tabbed_2_2" name = "__tabbed_2" type = "radio" / > < input id = "__tabbed_2_3" name = "__tabbed_2" type = "radio" / > < input id = "__tabbed_2_4" name = "__tabbed_2" type = "radio" / > < input id = "__tabbed_2_5" name = "__tabbed_2" type = "radio" / > < div class = "tabbed-labels" > < label for = "__tabbed_2_1" > LinkedListDeque< / label > < label for = "__tabbed_2_2" > pushLast()< / label > < label for = "__tabbed_2_3" > pushFirst()< / label > < label for = "__tabbed_2_4" > pollLast()< / label > < label for = "__tabbed_2_5" > pollFirst()< / label > < / div >
< div class = "tabbed-content" >
< div class = "tabbed-block" >
< p > < img alt = "linkedlist_deque" src = "../deque.assets/linkedlist_deque.png" / > < / p >
< / div >
< div class = "tabbed-block" >
< p > < img alt = "linkedlist_deque_push_last" src = "../deque.assets/linkedlist_deque_push_last.png" / > < / p >
< / div >
< div class = "tabbed-block" >
< p > < img alt = "linkedlist_deque_push_first" src = "../deque.assets/linkedlist_deque_push_first.png" / > < / p >
< / div >
< div class = "tabbed-block" >
< p > < img alt = "linkedlist_deque_poll_last" src = "../deque.assets/linkedlist_deque_poll_last.png" / > < / p >
< / div >
< div class = "tabbed-block" >
< p > < img alt = "linkedlist_deque_poll_first" src = "../deque.assets/linkedlist_deque_poll_first.png" / > < / p >
< / div >
< / div >
< / div >
< p > 以下是具体实现代码。< / p >
< div class = "tabbed-set tabbed-alternate" data-tabs = "3:10" > < input checked = "checked" id = "__tabbed_3_1" name = "__tabbed_3" type = "radio" / > < input id = "__tabbed_3_2" name = "__tabbed_3" type = "radio" / > < input id = "__tabbed_3_3" name = "__tabbed_3" type = "radio" / > < input id = "__tabbed_3_4" name = "__tabbed_3" type = "radio" / > < input id = "__tabbed_3_5" name = "__tabbed_3" type = "radio" / > < input id = "__tabbed_3_6" name = "__tabbed_3" type = "radio" / > < input id = "__tabbed_3_7" name = "__tabbed_3" type = "radio" / > < input id = "__tabbed_3_8" name = "__tabbed_3" type = "radio" / > < input id = "__tabbed_3_9" name = "__tabbed_3" type = "radio" / > < input id = "__tabbed_3_10" name = "__tabbed_3" type = "radio" / > < div class = "tabbed-labels" > < label for = "__tabbed_3_1" > Java< / label > < label for = "__tabbed_3_2" > C++< / label > < label for = "__tabbed_3_3" > Python< / label > < label for = "__tabbed_3_4" > Go< / label > < label for = "__tabbed_3_5" > JavaScript< / label > < label for = "__tabbed_3_6" > TypeScript< / label > < label for = "__tabbed_3_7" > C< / label > < label for = "__tabbed_3_8" > C#< / label > < label for = "__tabbed_3_9" > Swift< / label > < label for = "__tabbed_3_10" > Zig< / label > < / div >
< div class = "tabbed-content" >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > linkedlist_deque.java< / span > < pre > < span > < / span > < code > < a id = "__codelineno-10-1" name = "__codelineno-10-1" href = "#__codelineno-10-1" > < / a > < span class = "cm" > /* 双向链表结点 */< / span >
< a id = "__codelineno-10-2" name = "__codelineno-10-2" href = "#__codelineno-10-2" > < / a > < span class = "kd" > class< / span > < span class = "nc" > ListNode< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-3" name = "__codelineno-10-3" href = "#__codelineno-10-3" > < / a > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > val< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 结点值< / span >
< a id = "__codelineno-10-4" name = "__codelineno-10-4" href = "#__codelineno-10-4" > < / a > < span class = "w" > < / span > < span class = "n" > ListNode< / span > < span class = "w" > < / span > < span class = "n" > next< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 后继结点引用（指针）< / span >
< a id = "__codelineno-10-5" name = "__codelineno-10-5" href = "#__codelineno-10-5" > < / a > < span class = "w" > < / span > < span class = "n" > ListNode< / span > < span class = "w" > < / span > < span class = "n" > prev< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 前驱结点引用（指针）< / span >
< a id = "__codelineno-10-6" name = "__codelineno-10-6" href = "#__codelineno-10-6" > < / a > < span class = "w" > < / span > < span class = "n" > ListNode< / span > < span class = "p" > (< / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > val< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-7" name = "__codelineno-10-7" href = "#__codelineno-10-7" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "na" > val< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > val< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-8" name = "__codelineno-10-8" href = "#__codelineno-10-8" > < / a > < span class = "w" > < / span > < span class = "n" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-9" name = "__codelineno-10-9" href = "#__codelineno-10-9" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-10" name = "__codelineno-10-10" href = "#__codelineno-10-10" > < / a > < span class = "p" > }< / span >
< a id = "__codelineno-10-11" name = "__codelineno-10-11" href = "#__codelineno-10-11" > < / a >
< a id = "__codelineno-10-12" name = "__codelineno-10-12" href = "#__codelineno-10-12" > < / a > < span class = "cm" > /* 基于双向链表实现的双向队列 */< / span >
< a id = "__codelineno-10-13" name = "__codelineno-10-13" href = "#__codelineno-10-13" > < / a > < span class = "kd" > class< / span > < span class = "nc" > LinkedListDeque< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-14" name = "__codelineno-10-14" href = "#__codelineno-10-14" > < / a > < span class = "w" > < / span > < span class = "kd" > private< / span > < span class = "w" > < / span > < span class = "n" > ListNode< / span > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "p" > ,< / span > < span class = "w" > < / span > < span class = "n" > rear< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 头结点 front ，尾结点 rear< / span >
< a id = "__codelineno-10-15" name = "__codelineno-10-15" href = "#__codelineno-10-15" > < / a > < span class = "w" > < / span > < span class = "kd" > private< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > size< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "mi" > 0< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 双向队列的长度< / span >
< a id = "__codelineno-10-16" name = "__codelineno-10-16" href = "#__codelineno-10-16" > < / a >
< a id = "__codelineno-10-17" name = "__codelineno-10-17" href = "#__codelineno-10-17" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "nf" > LinkedListDeque< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-18" name = "__codelineno-10-18" href = "#__codelineno-10-18" > < / a > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-19" name = "__codelineno-10-19" href = "#__codelineno-10-19" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-20" name = "__codelineno-10-20" href = "#__codelineno-10-20" > < / a >
< a id = "__codelineno-10-21" name = "__codelineno-10-21" href = "#__codelineno-10-21" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 获取双向队列的长度 */< / span >
< a id = "__codelineno-10-22" name = "__codelineno-10-22" href = "#__codelineno-10-22" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "nf" > size< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-23" name = "__codelineno-10-23" href = "#__codelineno-10-23" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > size< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-24" name = "__codelineno-10-24" href = "#__codelineno-10-24" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-25" name = "__codelineno-10-25" href = "#__codelineno-10-25" > < / a >
< a id = "__codelineno-10-26" name = "__codelineno-10-26" href = "#__codelineno-10-26" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 判断双向队列是否为空 */< / span >
< a id = "__codelineno-10-27" name = "__codelineno-10-27" href = "#__codelineno-10-27" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > boolean< / span > < span class = "w" > < / span > < span class = "nf" > isEmpty< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-28" name = "__codelineno-10-28" href = "#__codelineno-10-28" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > size< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "o" > ==< / span > < span class = "w" > < / span > < span class = "mi" > 0< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-29" name = "__codelineno-10-29" href = "#__codelineno-10-29" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-30" name = "__codelineno-10-30" href = "#__codelineno-10-30" > < / a >
< a id = "__codelineno-10-31" name = "__codelineno-10-31" href = "#__codelineno-10-31" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 入队操作 */< / span >
< a id = "__codelineno-10-32" name = "__codelineno-10-32" href = "#__codelineno-10-32" > < / a > < span class = "w" > < / span > < span class = "kd" > private< / span > < span class = "w" > < / span > < span class = "kt" > void< / span > < span class = "w" > < / span > < span class = "nf" > push< / span > < span class = "p" > (< / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > num< / span > < span class = "p" > ,< / span > < span class = "w" > < / span > < span class = "kt" > boolean< / span > < span class = "w" > < / span > < span class = "n" > isFront< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-33" name = "__codelineno-10-33" href = "#__codelineno-10-33" > < / a > < span class = "w" > < / span > < span class = "n" > ListNode< / span > < span class = "w" > < / span > < span class = "n" > node< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > new< / span > < span class = "w" > < / span > < span class = "n" > ListNode< / span > < span class = "p" > (< / span > < span class = "n" > num< / span > < span class = "p" > );< / span >
< a id = "__codelineno-10-34" name = "__codelineno-10-34" href = "#__codelineno-10-34" > < / a > < span class = "w" > < / span > < span class = "c1" > // 若链表为空，则令 front, rear 都指向 node< / span >
< a id = "__codelineno-10-35" name = "__codelineno-10-35" href = "#__codelineno-10-35" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "n" > isEmpty< / span > < span class = "p" > ())< / span >
< a id = "__codelineno-10-36" name = "__codelineno-10-36" href = "#__codelineno-10-36" > < / a > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-37" name = "__codelineno-10-37" href = "#__codelineno-10-37" > < / a > < span class = "w" > < / span > < span class = "c1" > // 队首入队操作< / span >
< a id = "__codelineno-10-38" name = "__codelineno-10-38" href = "#__codelineno-10-38" > < / a > < span class = "w" > < / span > < span class = "k" > else< / span > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "n" > isFront< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-39" name = "__codelineno-10-39" href = "#__codelineno-10-39" > < / a > < span class = "w" > < / span > < span class = "c1" > // 将 node 添加至链表头部< / span >
< a id = "__codelineno-10-40" name = "__codelineno-10-40" href = "#__codelineno-10-40" > < / a > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "p" > .< / span > < span class = "na" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-41" name = "__codelineno-10-41" href = "#__codelineno-10-41" > < / a > < span class = "w" > < / span > < span class = "n" > node< / span > < span class = "p" > .< / span > < span class = "na" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-42" name = "__codelineno-10-42" href = "#__codelineno-10-42" > < / a > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > node< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 更新头结点< / span >
< a id = "__codelineno-10-43" name = "__codelineno-10-43" href = "#__codelineno-10-43" > < / a > < span class = "w" > < / span > < span class = "c1" > // 队尾入队操作< / span >
< a id = "__codelineno-10-44" name = "__codelineno-10-44" href = "#__codelineno-10-44" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span > < span class = "w" > < / span > < span class = "k" > else< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-45" name = "__codelineno-10-45" href = "#__codelineno-10-45" > < / a > < span class = "w" > < / span > < span class = "c1" > // 将 node 添加至链表尾部< / span >
< a id = "__codelineno-10-46" name = "__codelineno-10-46" href = "#__codelineno-10-46" > < / a > < span class = "w" > < / span > < span class = "n" > rear< / span > < span class = "p" > .< / span > < span class = "na" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-47" name = "__codelineno-10-47" href = "#__codelineno-10-47" > < / a > < span class = "w" > < / span > < span class = "n" > node< / span > < span class = "p" > .< / span > < span class = "na" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > rear< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-48" name = "__codelineno-10-48" href = "#__codelineno-10-48" > < / a > < span class = "w" > < / span > < span class = "n" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > node< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 更新尾结点< / span >
< a id = "__codelineno-10-49" name = "__codelineno-10-49" href = "#__codelineno-10-49" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-50" name = "__codelineno-10-50" href = "#__codelineno-10-50" > < / a > < span class = "w" > < / span > < span class = "n" > size< / span > < span class = "o" > ++< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 更新队列长度< / span >
< a id = "__codelineno-10-51" name = "__codelineno-10-51" href = "#__codelineno-10-51" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-52" name = "__codelineno-10-52" href = "#__codelineno-10-52" > < / a >
< a id = "__codelineno-10-53" name = "__codelineno-10-53" href = "#__codelineno-10-53" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队首入队 */< / span >
< a id = "__codelineno-10-54" name = "__codelineno-10-54" href = "#__codelineno-10-54" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > void< / span > < span class = "w" > < / span > < span class = "nf" > pushFirst< / span > < span class = "p" > (< / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > num< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-55" name = "__codelineno-10-55" href = "#__codelineno-10-55" > < / a > < span class = "w" > < / span > < span class = "n" > push< / span > < span class = "p" > (< / span > < span class = "n" > num< / span > < span class = "p" > ,< / span > < span class = "w" > < / span > < span class = "kc" > true< / span > < span class = "p" > );< / span >
< a id = "__codelineno-10-56" name = "__codelineno-10-56" href = "#__codelineno-10-56" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-57" name = "__codelineno-10-57" href = "#__codelineno-10-57" > < / a >
< a id = "__codelineno-10-58" name = "__codelineno-10-58" href = "#__codelineno-10-58" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队尾入队 */< / span >
< a id = "__codelineno-10-59" name = "__codelineno-10-59" href = "#__codelineno-10-59" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > void< / span > < span class = "w" > < / span > < span class = "nf" > pushLast< / span > < span class = "p" > (< / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > num< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-60" name = "__codelineno-10-60" href = "#__codelineno-10-60" > < / a > < span class = "w" > < / span > < span class = "n" > push< / span > < span class = "p" > (< / span > < span class = "n" > num< / span > < span class = "p" > ,< / span > < span class = "w" > < / span > < span class = "kc" > false< / span > < span class = "p" > );< / span >
< a id = "__codelineno-10-61" name = "__codelineno-10-61" href = "#__codelineno-10-61" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-62" name = "__codelineno-10-62" href = "#__codelineno-10-62" > < / a >
< a id = "__codelineno-10-63" name = "__codelineno-10-63" href = "#__codelineno-10-63" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 出队操作 */< / span >
< a id = "__codelineno-10-64" name = "__codelineno-10-64" href = "#__codelineno-10-64" > < / a > < span class = "w" > < / span > < span class = "kd" > private< / span > < span class = "w" > < / span > < span class = "n" > Integer< / span > < span class = "w" > < / span > < span class = "nf" > poll< / span > < span class = "p" > (< / span > < span class = "kt" > boolean< / span > < span class = "w" > < / span > < span class = "n" > isFront< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-65" name = "__codelineno-10-65" href = "#__codelineno-10-65" > < / a > < span class = "w" > < / span > < span class = "c1" > // 若队列为空，直接返回 null< / span >
< a id = "__codelineno-10-66" name = "__codelineno-10-66" href = "#__codelineno-10-66" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "n" > isEmpty< / span > < span class = "p" > ())< / span >
< a id = "__codelineno-10-67" name = "__codelineno-10-67" href = "#__codelineno-10-67" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-68" name = "__codelineno-10-68" href = "#__codelineno-10-68" > < / a > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > val< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-69" name = "__codelineno-10-69" href = "#__codelineno-10-69" > < / a > < span class = "w" > < / span > < span class = "c1" > // 队首出队操作< / span >
< a id = "__codelineno-10-70" name = "__codelineno-10-70" href = "#__codelineno-10-70" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "n" > isFront< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-71" name = "__codelineno-10-71" href = "#__codelineno-10-71" > < / a > < span class = "w" > < / span > < span class = "n" > val< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "p" > .< / span > < span class = "na" > val< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 暂存头结点值< / span >
< a id = "__codelineno-10-72" name = "__codelineno-10-72" href = "#__codelineno-10-72" > < / a > < span class = "w" > < / span > < span class = "c1" > // 删除头结点< / span >
< a id = "__codelineno-10-73" name = "__codelineno-10-73" href = "#__codelineno-10-73" > < / a > < span class = "w" > < / span > < span class = "n" > ListNode< / span > < span class = "w" > < / span > < span class = "n" > fNext< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "p" > .< / span > < span class = "na" > next< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-74" name = "__codelineno-10-74" href = "#__codelineno-10-74" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "n" > fNext< / span > < span class = "w" > < / span > < span class = "o" > !=< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-75" name = "__codelineno-10-75" href = "#__codelineno-10-75" > < / a > < span class = "w" > < / span > < span class = "n" > fNext< / span > < span class = "p" > .< / span > < span class = "na" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-76" name = "__codelineno-10-76" href = "#__codelineno-10-76" > < / a > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "p" > .< / span > < span class = "na" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-77" name = "__codelineno-10-77" href = "#__codelineno-10-77" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-78" name = "__codelineno-10-78" href = "#__codelineno-10-78" > < / a > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > fNext< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 更新头结点< / span >
< a id = "__codelineno-10-79" name = "__codelineno-10-79" href = "#__codelineno-10-79" > < / a > < span class = "w" > < / span > < span class = "c1" > // 队尾出队操作< / span >
< a id = "__codelineno-10-80" name = "__codelineno-10-80" href = "#__codelineno-10-80" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span > < span class = "w" > < / span > < span class = "k" > else< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-81" name = "__codelineno-10-81" href = "#__codelineno-10-81" > < / a > < span class = "w" > < / span > < span class = "n" > val< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > rear< / span > < span class = "p" > .< / span > < span class = "na" > val< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 暂存尾结点值< / span >
< a id = "__codelineno-10-82" name = "__codelineno-10-82" href = "#__codelineno-10-82" > < / a > < span class = "w" > < / span > < span class = "c1" > // 删除尾结点< / span >
< a id = "__codelineno-10-83" name = "__codelineno-10-83" href = "#__codelineno-10-83" > < / a > < span class = "w" > < / span > < span class = "n" > ListNode< / span > < span class = "w" > < / span > < span class = "n" > rPrev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > rear< / span > < span class = "p" > .< / span > < span class = "na" > prev< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-84" name = "__codelineno-10-84" href = "#__codelineno-10-84" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "n" > rPrev< / span > < span class = "w" > < / span > < span class = "o" > !=< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-85" name = "__codelineno-10-85" href = "#__codelineno-10-85" > < / a > < span class = "w" > < / span > < span class = "n" > rPrev< / span > < span class = "p" > .< / span > < span class = "na" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-86" name = "__codelineno-10-86" href = "#__codelineno-10-86" > < / a > < span class = "w" > < / span > < span class = "n" > rear< / span > < span class = "p" > .< / span > < span class = "na" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-87" name = "__codelineno-10-87" href = "#__codelineno-10-87" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-88" name = "__codelineno-10-88" href = "#__codelineno-10-88" > < / a > < span class = "w" > < / span > < span class = "n" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > rPrev< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 更新尾结点< / span >
< a id = "__codelineno-10-89" name = "__codelineno-10-89" href = "#__codelineno-10-89" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-90" name = "__codelineno-10-90" href = "#__codelineno-10-90" > < / a > < span class = "w" > < / span > < span class = "n" > size< / span > < span class = "o" > --< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 更新队列长度< / span >
< a id = "__codelineno-10-91" name = "__codelineno-10-91" href = "#__codelineno-10-91" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > val< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-92" name = "__codelineno-10-92" href = "#__codelineno-10-92" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-93" name = "__codelineno-10-93" href = "#__codelineno-10-93" > < / a >
< a id = "__codelineno-10-94" name = "__codelineno-10-94" href = "#__codelineno-10-94" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队首出队 */< / span >
< a id = "__codelineno-10-95" name = "__codelineno-10-95" href = "#__codelineno-10-95" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "n" > Integer< / span > < span class = "w" > < / span > < span class = "nf" > pollFirst< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-96" name = "__codelineno-10-96" href = "#__codelineno-10-96" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > poll< / span > < span class = "p" > (< / span > < span class = "kc" > true< / span > < span class = "p" > );< / span >
< a id = "__codelineno-10-97" name = "__codelineno-10-97" href = "#__codelineno-10-97" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-98" name = "__codelineno-10-98" href = "#__codelineno-10-98" > < / a >
< a id = "__codelineno-10-99" name = "__codelineno-10-99" href = "#__codelineno-10-99" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队尾出队 */< / span >
< a id = "__codelineno-10-100" name = "__codelineno-10-100" href = "#__codelineno-10-100" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "n" > Integer< / span > < span class = "w" > < / span > < span class = "nf" > pollLast< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-101" name = "__codelineno-10-101" href = "#__codelineno-10-101" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > poll< / span > < span class = "p" > (< / span > < span class = "kc" > false< / span > < span class = "p" > );< / span >
< a id = "__codelineno-10-102" name = "__codelineno-10-102" href = "#__codelineno-10-102" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-103" name = "__codelineno-10-103" href = "#__codelineno-10-103" > < / a >
< a id = "__codelineno-10-104" name = "__codelineno-10-104" href = "#__codelineno-10-104" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 访问队首元素 */< / span >
< a id = "__codelineno-10-105" name = "__codelineno-10-105" href = "#__codelineno-10-105" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "n" > Integer< / span > < span class = "w" > < / span > < span class = "nf" > peekFirst< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-106" name = "__codelineno-10-106" href = "#__codelineno-10-106" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > isEmpty< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "o" > ?< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "w" > < / span > < span class = "p" > :< / span > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "p" > .< / span > < span class = "na" > val< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-107" name = "__codelineno-10-107" href = "#__codelineno-10-107" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-108" name = "__codelineno-10-108" href = "#__codelineno-10-108" > < / a >
< a id = "__codelineno-10-109" name = "__codelineno-10-109" href = "#__codelineno-10-109" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 访问队尾元素 */< / span >
< a id = "__codelineno-10-110" name = "__codelineno-10-110" href = "#__codelineno-10-110" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "n" > Integer< / span > < span class = "w" > < / span > < span class = "nf" > peekLast< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-111" name = "__codelineno-10-111" href = "#__codelineno-10-111" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > isEmpty< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "o" > ?< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "w" > < / span > < span class = "p" > :< / span > < span class = "w" > < / span > < span class = "n" > rear< / span > < span class = "p" > .< / span > < span class = "na" > val< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-112" name = "__codelineno-10-112" href = "#__codelineno-10-112" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-113" name = "__codelineno-10-113" href = "#__codelineno-10-113" > < / a >
< a id = "__codelineno-10-114" name = "__codelineno-10-114" href = "#__codelineno-10-114" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 返回数组用于打印 */< / span >
< a id = "__codelineno-10-115" name = "__codelineno-10-115" href = "#__codelineno-10-115" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "o" > []< / span > < span class = "w" > < / span > < span class = "nf" > toArray< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-116" name = "__codelineno-10-116" href = "#__codelineno-10-116" > < / a > < span class = "w" > < / span > < span class = "n" > ListNode< / span > < span class = "w" > < / span > < span class = "n" > node< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-117" name = "__codelineno-10-117" href = "#__codelineno-10-117" > < / a > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "o" > []< / span > < span class = "w" > < / span > < span class = "n" > res< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > new< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "o" > [< / span > < span class = "n" > size< / span > < span class = "p" > ()< / span > < span class = "o" > ]< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-118" name = "__codelineno-10-118" href = "#__codelineno-10-118" > < / a > < span class = "w" > < / span > < span class = "k" > for< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > i< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "mi" > 0< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "n" > i< / span > < span class = "w" > < / span > < span class = "o" > < < / span > < span class = "w" > < / span > < span class = "n" > res< / span > < span class = "p" > .< / span > < span class = "na" > length< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "n" > i< / span > < span class = "o" > ++< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-10-119" name = "__codelineno-10-119" href = "#__codelineno-10-119" > < / a > < span class = "w" > < / span > < span class = "n" > res< / span > < span class = "o" > [< / span > < span class = "n" > i< / span > < span class = "o" > ]< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > node< / span > < span class = "p" > .< / span > < span class = "na" > val< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-120" name = "__codelineno-10-120" href = "#__codelineno-10-120" > < / a > < span class = "w" > < / span > < span class = "n" > node< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > node< / span > < span class = "p" > .< / span > < span class = "na" > next< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-121" name = "__codelineno-10-121" href = "#__codelineno-10-121" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-122" name = "__codelineno-10-122" href = "#__codelineno-10-122" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > res< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-10-123" name = "__codelineno-10-123" href = "#__codelineno-10-123" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-10-124" name = "__codelineno-10-124" href = "#__codelineno-10-124" > < / a > < span class = "p" > }< / span >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > linkedlist_deque.cpp< / span > < pre > < span > < / span > < code > < a id = "__codelineno-11-1" name = "__codelineno-11-1" href = "#__codelineno-11-1" > < / a >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > linkedlist_deque.py< / span > < pre > < span > < / span > < code > < a id = "__codelineno-12-1" name = "__codelineno-12-1" href = "#__codelineno-12-1" > < / a >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > linkedlist_deque.go< / span > < pre > < span > < / span > < code > < a id = "__codelineno-13-1" name = "__codelineno-13-1" href = "#__codelineno-13-1" > < / a >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > linkedlist_deque.js< / span > < pre > < span > < / span > < code > < a id = "__codelineno-14-1" name = "__codelineno-14-1" href = "#__codelineno-14-1" > < / a > < span class = "cm" > /* 双向链表结点 */< / span >
< a id = "__codelineno-14-2" name = "__codelineno-14-2" href = "#__codelineno-14-2" > < / a > < span class = "kd" > class< / span > < span class = "w" > < / span > < span class = "nx" > ListNode< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-3" name = "__codelineno-14-3" href = "#__codelineno-14-3" > < / a > < span class = "w" > < / span > < span class = "nx" > prev< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 前驱结点引用 (指针)< / span >
< a id = "__codelineno-14-4" name = "__codelineno-14-4" href = "#__codelineno-14-4" > < / a > < span class = "w" > < / span > < span class = "nx" > next< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 后继结点引用 (指针)< / span >
< a id = "__codelineno-14-5" name = "__codelineno-14-5" href = "#__codelineno-14-5" > < / a > < span class = "w" > < / span > < span class = "nx" > val< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 结点值< / span >
< a id = "__codelineno-14-6" name = "__codelineno-14-6" href = "#__codelineno-14-6" > < / a >
< a id = "__codelineno-14-7" name = "__codelineno-14-7" href = "#__codelineno-14-7" > < / a > < span class = "w" > < / span > < span class = "kr" > constructor< / span > < span class = "p" > (< / span > < span class = "nx" > val< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-8" name = "__codelineno-14-8" href = "#__codelineno-14-8" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > val< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > val< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-9" name = "__codelineno-14-9" href = "#__codelineno-14-9" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-10" name = "__codelineno-14-10" href = "#__codelineno-14-10" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-11" name = "__codelineno-14-11" href = "#__codelineno-14-11" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-12" name = "__codelineno-14-12" href = "#__codelineno-14-12" > < / a > < span class = "p" > }< / span >
< a id = "__codelineno-14-13" name = "__codelineno-14-13" href = "#__codelineno-14-13" > < / a >
< a id = "__codelineno-14-14" name = "__codelineno-14-14" href = "#__codelineno-14-14" > < / a > < span class = "cm" > /* 基于双向链表实现的双向队列 */< / span >
< a id = "__codelineno-14-15" name = "__codelineno-14-15" href = "#__codelineno-14-15" > < / a > < span class = "kd" > class< / span > < span class = "w" > < / span > < span class = "nx" > LinkedListDeque< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-16" name = "__codelineno-14-16" href = "#__codelineno-14-16" > < / a > < span class = "w" > < / span > < span class = "nx" > front< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 头结点 front< / span >
< a id = "__codelineno-14-17" name = "__codelineno-14-17" href = "#__codelineno-14-17" > < / a > < span class = "w" > < / span > < span class = "nx" > rear< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 尾结点 rear< / span >
< a id = "__codelineno-14-18" name = "__codelineno-14-18" href = "#__codelineno-14-18" > < / a > < span class = "w" > < / span > < span class = "nx" > len< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 双向队列的长度< / span >
< a id = "__codelineno-14-19" name = "__codelineno-14-19" href = "#__codelineno-14-19" > < / a >
< a id = "__codelineno-14-20" name = "__codelineno-14-20" href = "#__codelineno-14-20" > < / a > < span class = "w" > < / span > < span class = "kr" > constructor< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-21" name = "__codelineno-14-21" href = "#__codelineno-14-21" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-22" name = "__codelineno-14-22" href = "#__codelineno-14-22" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-23" name = "__codelineno-14-23" href = "#__codelineno-14-23" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-24" name = "__codelineno-14-24" href = "#__codelineno-14-24" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-25" name = "__codelineno-14-25" href = "#__codelineno-14-25" > < / a >
< a id = "__codelineno-14-26" name = "__codelineno-14-26" href = "#__codelineno-14-26" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队尾入队操作 */< / span >
< a id = "__codelineno-14-27" name = "__codelineno-14-27" href = "#__codelineno-14-27" > < / a > < span class = "w" > < / span > < span class = "nx" > pushLast< / span > < span class = "p" > (< / span > < span class = "nx" > val< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-28" name = "__codelineno-14-28" href = "#__codelineno-14-28" > < / a > < span class = "w" > < / span > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "ow" > new< / span > < span class = "w" > < / span > < span class = "nx" > ListNode< / span > < span class = "p" > (< / span > < span class = "nx" > val< / span > < span class = "p" > );< / span >
< a id = "__codelineno-14-29" name = "__codelineno-14-29" href = "#__codelineno-14-29" > < / a > < span class = "w" > < / span > < span class = "c1" > // 若链表为空，则令 front, rear 都指向 node< / span >
< a id = "__codelineno-14-30" name = "__codelineno-14-30" href = "#__codelineno-14-30" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-31" name = "__codelineno-14-31" href = "#__codelineno-14-31" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-32" name = "__codelineno-14-32" href = "#__codelineno-14-32" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-33" name = "__codelineno-14-33" href = "#__codelineno-14-33" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span > < span class = "w" > < / span > < span class = "k" > else< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-34" name = "__codelineno-14-34" href = "#__codelineno-14-34" > < / a > < span class = "w" > < / span > < span class = "c1" > // 将 node 添加至链表尾部< / span >
< a id = "__codelineno-14-35" name = "__codelineno-14-35" href = "#__codelineno-14-35" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "p" > .< / span > < span class = "nx" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-36" name = "__codelineno-14-36" href = "#__codelineno-14-36" > < / a > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > .< / span > < span class = "nx" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-37" name = "__codelineno-14-37" href = "#__codelineno-14-37" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 更新尾结点< / span >
< a id = "__codelineno-14-38" name = "__codelineno-14-38" href = "#__codelineno-14-38" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-39" name = "__codelineno-14-39" href = "#__codelineno-14-39" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "o" > ++< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-40" name = "__codelineno-14-40" href = "#__codelineno-14-40" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-41" name = "__codelineno-14-41" href = "#__codelineno-14-41" > < / a >
< a id = "__codelineno-14-42" name = "__codelineno-14-42" href = "#__codelineno-14-42" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队首入队操作 */< / span >
< a id = "__codelineno-14-43" name = "__codelineno-14-43" href = "#__codelineno-14-43" > < / a > < span class = "w" > < / span > < span class = "nx" > pushFirst< / span > < span class = "p" > (< / span > < span class = "nx" > val< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-44" name = "__codelineno-14-44" href = "#__codelineno-14-44" > < / a > < span class = "w" > < / span > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "ow" > new< / span > < span class = "w" > < / span > < span class = "nx" > ListNode< / span > < span class = "p" > (< / span > < span class = "nx" > val< / span > < span class = "p" > );< / span >
< a id = "__codelineno-14-45" name = "__codelineno-14-45" href = "#__codelineno-14-45" > < / a > < span class = "w" > < / span > < span class = "c1" > // 若链表为空，则令 front, rear 都指向 node< / span >
< a id = "__codelineno-14-46" name = "__codelineno-14-46" href = "#__codelineno-14-46" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-47" name = "__codelineno-14-47" href = "#__codelineno-14-47" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-48" name = "__codelineno-14-48" href = "#__codelineno-14-48" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-49" name = "__codelineno-14-49" href = "#__codelineno-14-49" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span > < span class = "w" > < / span > < span class = "k" > else< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-50" name = "__codelineno-14-50" href = "#__codelineno-14-50" > < / a > < span class = "w" > < / span > < span class = "c1" > // 将 node 添加至链表头部< / span >
< a id = "__codelineno-14-51" name = "__codelineno-14-51" href = "#__codelineno-14-51" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "p" > .< / span > < span class = "nx" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-52" name = "__codelineno-14-52" href = "#__codelineno-14-52" > < / a > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > .< / span > < span class = "nx" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-53" name = "__codelineno-14-53" href = "#__codelineno-14-53" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 更新头结点< / span >
< a id = "__codelineno-14-54" name = "__codelineno-14-54" href = "#__codelineno-14-54" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-55" name = "__codelineno-14-55" href = "#__codelineno-14-55" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "o" > ++< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-56" name = "__codelineno-14-56" href = "#__codelineno-14-56" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-57" name = "__codelineno-14-57" href = "#__codelineno-14-57" > < / a >
< a id = "__codelineno-14-58" name = "__codelineno-14-58" href = "#__codelineno-14-58" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队尾出队操作 */< / span >
< a id = "__codelineno-14-59" name = "__codelineno-14-59" href = "#__codelineno-14-59" > < / a > < span class = "w" > < / span > < span class = "nx" > pollLast< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-60" name = "__codelineno-14-60" href = "#__codelineno-14-60" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-61" name = "__codelineno-14-61" href = "#__codelineno-14-61" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-62" name = "__codelineno-14-62" href = "#__codelineno-14-62" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-63" name = "__codelineno-14-63" href = "#__codelineno-14-63" > < / a > < span class = "w" > < / span > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > value< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "p" > .< / span > < span class = "nx" > val< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 存储尾结点值< / span >
< a id = "__codelineno-14-64" name = "__codelineno-14-64" href = "#__codelineno-14-64" > < / a > < span class = "w" > < / span > < span class = "c1" > // 删除尾结点< / span >
< a id = "__codelineno-14-65" name = "__codelineno-14-65" href = "#__codelineno-14-65" > < / a > < span class = "w" > < / span > < span class = "kd" > let< / span > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "p" > .< / span > < span class = "nx" > prev< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-66" name = "__codelineno-14-66" href = "#__codelineno-14-66" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "nx" > temp< / span > < span class = "w" > < / span > < span class = "o" > !==< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-67" name = "__codelineno-14-67" href = "#__codelineno-14-67" > < / a > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "p" > .< / span > < span class = "nx" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-68" name = "__codelineno-14-68" href = "#__codelineno-14-68" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "p" > .< / span > < span class = "nx" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-69" name = "__codelineno-14-69" href = "#__codelineno-14-69" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-70" name = "__codelineno-14-70" href = "#__codelineno-14-70" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 更新尾结点< / span >
< a id = "__codelineno-14-71" name = "__codelineno-14-71" href = "#__codelineno-14-71" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "o" > --< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-72" name = "__codelineno-14-72" href = "#__codelineno-14-72" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "nx" > value< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-73" name = "__codelineno-14-73" href = "#__codelineno-14-73" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-74" name = "__codelineno-14-74" href = "#__codelineno-14-74" > < / a >
< a id = "__codelineno-14-75" name = "__codelineno-14-75" href = "#__codelineno-14-75" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队首出队操作 */< / span >
< a id = "__codelineno-14-76" name = "__codelineno-14-76" href = "#__codelineno-14-76" > < / a > < span class = "w" > < / span > < span class = "nx" > pollFirst< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-77" name = "__codelineno-14-77" href = "#__codelineno-14-77" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-78" name = "__codelineno-14-78" href = "#__codelineno-14-78" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-79" name = "__codelineno-14-79" href = "#__codelineno-14-79" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-80" name = "__codelineno-14-80" href = "#__codelineno-14-80" > < / a > < span class = "w" > < / span > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > value< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "p" > .< / span > < span class = "nx" > val< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 存储尾结点值< / span >
< a id = "__codelineno-14-81" name = "__codelineno-14-81" href = "#__codelineno-14-81" > < / a > < span class = "w" > < / span > < span class = "c1" > // 删除头结点< / span >
< a id = "__codelineno-14-82" name = "__codelineno-14-82" href = "#__codelineno-14-82" > < / a > < span class = "w" > < / span > < span class = "kd" > let< / span > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "p" > .< / span > < span class = "nx" > next< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-83" name = "__codelineno-14-83" href = "#__codelineno-14-83" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "nx" > temp< / span > < span class = "w" > < / span > < span class = "o" > !==< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-84" name = "__codelineno-14-84" href = "#__codelineno-14-84" > < / a > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "p" > .< / span > < span class = "nx" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-85" name = "__codelineno-14-85" href = "#__codelineno-14-85" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "p" > .< / span > < span class = "nx" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-86" name = "__codelineno-14-86" href = "#__codelineno-14-86" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-87" name = "__codelineno-14-87" href = "#__codelineno-14-87" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 更新头结点< / span >
< a id = "__codelineno-14-88" name = "__codelineno-14-88" href = "#__codelineno-14-88" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "o" > --< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-89" name = "__codelineno-14-89" href = "#__codelineno-14-89" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "nx" > value< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-90" name = "__codelineno-14-90" href = "#__codelineno-14-90" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-91" name = "__codelineno-14-91" href = "#__codelineno-14-91" > < / a >
< a id = "__codelineno-14-92" name = "__codelineno-14-92" href = "#__codelineno-14-92" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 访问队尾元素 */< / span >
< a id = "__codelineno-14-93" name = "__codelineno-14-93" href = "#__codelineno-14-93" > < / a > < span class = "w" > < / span > < span class = "nx" > peekLast< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-94" name = "__codelineno-14-94" href = "#__codelineno-14-94" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "w" > < / span > < span class = "o" > ?< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "w" > < / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "p" > .< / span > < span class = "nx" > val< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-95" name = "__codelineno-14-95" href = "#__codelineno-14-95" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-96" name = "__codelineno-14-96" href = "#__codelineno-14-96" > < / a >
< a id = "__codelineno-14-97" name = "__codelineno-14-97" href = "#__codelineno-14-97" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 访问队首元素 */< / span >
< a id = "__codelineno-14-98" name = "__codelineno-14-98" href = "#__codelineno-14-98" > < / a > < span class = "w" > < / span > < span class = "nx" > peekFirst< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-99" name = "__codelineno-14-99" href = "#__codelineno-14-99" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "w" > < / span > < span class = "o" > ?< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "w" > < / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "p" > .< / span > < span class = "nx" > val< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-100" name = "__codelineno-14-100" href = "#__codelineno-14-100" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-101" name = "__codelineno-14-101" href = "#__codelineno-14-101" > < / a >
< a id = "__codelineno-14-102" name = "__codelineno-14-102" href = "#__codelineno-14-102" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 获取双向队列的长度 */< / span >
< a id = "__codelineno-14-103" name = "__codelineno-14-103" href = "#__codelineno-14-103" > < / a > < span class = "w" > < / span > < span class = "nx" > size< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-104" name = "__codelineno-14-104" href = "#__codelineno-14-104" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-105" name = "__codelineno-14-105" href = "#__codelineno-14-105" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-106" name = "__codelineno-14-106" href = "#__codelineno-14-106" > < / a >
< a id = "__codelineno-14-107" name = "__codelineno-14-107" href = "#__codelineno-14-107" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 判断双向队列是否为空 */< / span >
< a id = "__codelineno-14-108" name = "__codelineno-14-108" href = "#__codelineno-14-108" > < / a > < span class = "w" > < / span > < span class = "nx" > isEmpty< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-109" name = "__codelineno-14-109" href = "#__codelineno-14-109" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-110" name = "__codelineno-14-110" href = "#__codelineno-14-110" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-111" name = "__codelineno-14-111" href = "#__codelineno-14-111" > < / a >
< a id = "__codelineno-14-112" name = "__codelineno-14-112" href = "#__codelineno-14-112" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 打印双向队列 */< / span >
< a id = "__codelineno-14-113" name = "__codelineno-14-113" href = "#__codelineno-14-113" > < / a > < span class = "w" > < / span > < span class = "nx" > print< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-114" name = "__codelineno-14-114" href = "#__codelineno-14-114" > < / a > < span class = "w" > < / span > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > arr< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "p" > [];< / span >
< a id = "__codelineno-14-115" name = "__codelineno-14-115" href = "#__codelineno-14-115" > < / a > < span class = "w" > < / span > < span class = "kd" > let< / span > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-116" name = "__codelineno-14-116" href = "#__codelineno-14-116" > < / a > < span class = "w" > < / span > < span class = "k" > while< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "nx" > temp< / span > < span class = "w" > < / span > < span class = "o" > !==< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-14-117" name = "__codelineno-14-117" href = "#__codelineno-14-117" > < / a > < span class = "w" > < / span > < span class = "nx" > arr< / span > < span class = "p" > .< / span > < span class = "nx" > push< / span > < span class = "p" > (< / span > < span class = "nx" > temp< / span > < span class = "p" > .< / span > < span class = "nx" > val< / span > < span class = "p" > );< / span >
< a id = "__codelineno-14-118" name = "__codelineno-14-118" href = "#__codelineno-14-118" > < / a > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "p" > .< / span > < span class = "nx" > next< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-14-119" name = "__codelineno-14-119" href = "#__codelineno-14-119" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-120" name = "__codelineno-14-120" href = "#__codelineno-14-120" > < / a > < span class = "w" > < / span > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " [" < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > arr< / span > < span class = "p" > .< / span > < span class = "nx" > join< / span > < span class = "p" > (< / span > < span class = "s2" > " , " < / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "s2" > " ]" < / span > < span class = "p" > );< / span >
< a id = "__codelineno-14-121" name = "__codelineno-14-121" href = "#__codelineno-14-121" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-14-122" name = "__codelineno-14-122" href = "#__codelineno-14-122" > < / a > < span class = "p" > }< / span >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > linkedlist_deque.ts< / span > < pre > < span > < / span > < code > < a id = "__codelineno-15-1" name = "__codelineno-15-1" href = "#__codelineno-15-1" > < / a > < span class = "cm" > /* 双向链表结点 */< / span >
< a id = "__codelineno-15-2" name = "__codelineno-15-2" href = "#__codelineno-15-2" > < / a > < span class = "kd" > class< / span > < span class = "w" > < / span > < span class = "nx" > ListNode< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-3" name = "__codelineno-15-3" href = "#__codelineno-15-3" > < / a > < span class = "w" > < / span > < span class = "nx" > prev< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > ListNode< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 前驱结点引用 (指针)< / span >
< a id = "__codelineno-15-4" name = "__codelineno-15-4" href = "#__codelineno-15-4" > < / a > < span class = "w" > < / span > < span class = "nx" > next< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > ListNode< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 后继结点引用 (指针)< / span >
< a id = "__codelineno-15-5" name = "__codelineno-15-5" href = "#__codelineno-15-5" > < / a > < span class = "w" > < / span > < span class = "nx" > val< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 结点值< / span >
< a id = "__codelineno-15-6" name = "__codelineno-15-6" href = "#__codelineno-15-6" > < / a >
< a id = "__codelineno-15-7" name = "__codelineno-15-7" href = "#__codelineno-15-7" > < / a > < span class = "w" > < / span > < span class = "kr" > constructor< / span > < span class = "p" > (< / span > < span class = "nx" > val< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-8" name = "__codelineno-15-8" href = "#__codelineno-15-8" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > val< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > val< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-9" name = "__codelineno-15-9" href = "#__codelineno-15-9" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-10" name = "__codelineno-15-10" href = "#__codelineno-15-10" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-11" name = "__codelineno-15-11" href = "#__codelineno-15-11" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-12" name = "__codelineno-15-12" href = "#__codelineno-15-12" > < / a > < span class = "p" > }< / span >
< a id = "__codelineno-15-13" name = "__codelineno-15-13" href = "#__codelineno-15-13" > < / a >
< a id = "__codelineno-15-14" name = "__codelineno-15-14" href = "#__codelineno-15-14" > < / a > < span class = "cm" > /* 基于双向链表实现的双向队列 */< / span >
< a id = "__codelineno-15-15" name = "__codelineno-15-15" href = "#__codelineno-15-15" > < / a > < span class = "kd" > class< / span > < span class = "w" > < / span > < span class = "nx" > LinkedListDeque< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-16" name = "__codelineno-15-16" href = "#__codelineno-15-16" > < / a > < span class = "w" > < / span > < span class = "nx" > front< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > ListNode< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 头结点 front< / span >
< a id = "__codelineno-15-17" name = "__codelineno-15-17" href = "#__codelineno-15-17" > < / a > < span class = "w" > < / span > < span class = "nx" > rear< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > ListNode< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 尾结点 rear< / span >
< a id = "__codelineno-15-18" name = "__codelineno-15-18" href = "#__codelineno-15-18" > < / a > < span class = "w" > < / span > < span class = "nx" > len< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 双向队列的长度< / span >
< a id = "__codelineno-15-19" name = "__codelineno-15-19" href = "#__codelineno-15-19" > < / a >
< a id = "__codelineno-15-20" name = "__codelineno-15-20" href = "#__codelineno-15-20" > < / a > < span class = "w" > < / span > < span class = "kr" > constructor< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-21" name = "__codelineno-15-21" href = "#__codelineno-15-21" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-22" name = "__codelineno-15-22" href = "#__codelineno-15-22" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-23" name = "__codelineno-15-23" href = "#__codelineno-15-23" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-24" name = "__codelineno-15-24" href = "#__codelineno-15-24" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-25" name = "__codelineno-15-25" href = "#__codelineno-15-25" > < / a >
< a id = "__codelineno-15-26" name = "__codelineno-15-26" href = "#__codelineno-15-26" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队尾入队操作 */< / span >
< a id = "__codelineno-15-27" name = "__codelineno-15-27" href = "#__codelineno-15-27" > < / a > < span class = "w" > < / span > < span class = "nx" > pushLast< / span > < span class = "p" > (< / span > < span class = "nx" > val< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "p" > )< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "ow" > void< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-28" name = "__codelineno-15-28" href = "#__codelineno-15-28" > < / a > < span class = "w" > < / span > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > ListNode< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "ow" > new< / span > < span class = "w" > < / span > < span class = "nx" > ListNode< / span > < span class = "p" > (< / span > < span class = "nx" > val< / span > < span class = "p" > );< / span >
< a id = "__codelineno-15-29" name = "__codelineno-15-29" href = "#__codelineno-15-29" > < / a > < span class = "w" > < / span > < span class = "c1" > // 若链表为空，则令 front, rear 都指向 node< / span >
< a id = "__codelineno-15-30" name = "__codelineno-15-30" href = "#__codelineno-15-30" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-31" name = "__codelineno-15-31" href = "#__codelineno-15-31" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-32" name = "__codelineno-15-32" href = "#__codelineno-15-32" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-33" name = "__codelineno-15-33" href = "#__codelineno-15-33" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span > < span class = "w" > < / span > < span class = "k" > else< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-34" name = "__codelineno-15-34" href = "#__codelineno-15-34" > < / a > < span class = "w" > < / span > < span class = "c1" > // 将 node 添加至链表尾部< / span >
< a id = "__codelineno-15-35" name = "__codelineno-15-35" href = "#__codelineno-15-35" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "p" > .< / span > < span class = "nx" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-36" name = "__codelineno-15-36" href = "#__codelineno-15-36" > < / a > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > .< / span > < span class = "nx" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-37" name = "__codelineno-15-37" href = "#__codelineno-15-37" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 更新尾结点< / span >
< a id = "__codelineno-15-38" name = "__codelineno-15-38" href = "#__codelineno-15-38" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-39" name = "__codelineno-15-39" href = "#__codelineno-15-39" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "o" > ++< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-40" name = "__codelineno-15-40" href = "#__codelineno-15-40" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-41" name = "__codelineno-15-41" href = "#__codelineno-15-41" > < / a >
< a id = "__codelineno-15-42" name = "__codelineno-15-42" href = "#__codelineno-15-42" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队首入队操作 */< / span >
< a id = "__codelineno-15-43" name = "__codelineno-15-43" href = "#__codelineno-15-43" > < / a > < span class = "w" > < / span > < span class = "nx" > pushFirst< / span > < span class = "p" > (< / span > < span class = "nx" > val< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "p" > )< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "ow" > void< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-44" name = "__codelineno-15-44" href = "#__codelineno-15-44" > < / a > < span class = "w" > < / span > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > ListNode< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "ow" > new< / span > < span class = "w" > < / span > < span class = "nx" > ListNode< / span > < span class = "p" > (< / span > < span class = "nx" > val< / span > < span class = "p" > );< / span >
< a id = "__codelineno-15-45" name = "__codelineno-15-45" href = "#__codelineno-15-45" > < / a > < span class = "w" > < / span > < span class = "c1" > // 若链表为空，则令 front, rear 都指向 node< / span >
< a id = "__codelineno-15-46" name = "__codelineno-15-46" href = "#__codelineno-15-46" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-47" name = "__codelineno-15-47" href = "#__codelineno-15-47" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-48" name = "__codelineno-15-48" href = "#__codelineno-15-48" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-49" name = "__codelineno-15-49" href = "#__codelineno-15-49" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span > < span class = "w" > < / span > < span class = "k" > else< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-50" name = "__codelineno-15-50" href = "#__codelineno-15-50" > < / a > < span class = "w" > < / span > < span class = "c1" > // 将 node 添加至链表头部< / span >
< a id = "__codelineno-15-51" name = "__codelineno-15-51" href = "#__codelineno-15-51" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "p" > .< / span > < span class = "nx" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-52" name = "__codelineno-15-52" href = "#__codelineno-15-52" > < / a > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > .< / span > < span class = "nx" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-53" name = "__codelineno-15-53" href = "#__codelineno-15-53" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > node< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 更新头结点< / span >
< a id = "__codelineno-15-54" name = "__codelineno-15-54" href = "#__codelineno-15-54" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-55" name = "__codelineno-15-55" href = "#__codelineno-15-55" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "o" > ++< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-56" name = "__codelineno-15-56" href = "#__codelineno-15-56" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-57" name = "__codelineno-15-57" href = "#__codelineno-15-57" > < / a >
< a id = "__codelineno-15-58" name = "__codelineno-15-58" href = "#__codelineno-15-58" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队尾出队操作 */< / span >
< a id = "__codelineno-15-59" name = "__codelineno-15-59" href = "#__codelineno-15-59" > < / a > < span class = "w" > < / span > < span class = "nx" > pollLast< / span > < span class = "p" > ()< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-60" name = "__codelineno-15-60" href = "#__codelineno-15-60" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-61" name = "__codelineno-15-61" href = "#__codelineno-15-61" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-62" name = "__codelineno-15-62" href = "#__codelineno-15-62" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-63" name = "__codelineno-15-63" href = "#__codelineno-15-63" > < / a > < span class = "w" > < / span > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > value< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "p" > .< / span > < span class = "nx" > val< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 存储尾结点值< / span >
< a id = "__codelineno-15-64" name = "__codelineno-15-64" href = "#__codelineno-15-64" > < / a > < span class = "w" > < / span > < span class = "c1" > // 删除尾结点< / span >
< a id = "__codelineno-15-65" name = "__codelineno-15-65" href = "#__codelineno-15-65" > < / a > < span class = "w" > < / span > < span class = "kd" > let< / span > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > ListNode< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "p" > .< / span > < span class = "nx" > prev< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-66" name = "__codelineno-15-66" href = "#__codelineno-15-66" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "nx" > temp< / span > < span class = "w" > < / span > < span class = "o" > !==< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-67" name = "__codelineno-15-67" href = "#__codelineno-15-67" > < / a > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "p" > .< / span > < span class = "nx" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-68" name = "__codelineno-15-68" href = "#__codelineno-15-68" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "p" > .< / span > < span class = "nx" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-69" name = "__codelineno-15-69" href = "#__codelineno-15-69" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-70" name = "__codelineno-15-70" href = "#__codelineno-15-70" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 更新尾结点< / span >
< a id = "__codelineno-15-71" name = "__codelineno-15-71" href = "#__codelineno-15-71" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "o" > --< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-72" name = "__codelineno-15-72" href = "#__codelineno-15-72" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "nx" > value< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-73" name = "__codelineno-15-73" href = "#__codelineno-15-73" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-74" name = "__codelineno-15-74" href = "#__codelineno-15-74" > < / a >
< a id = "__codelineno-15-75" name = "__codelineno-15-75" href = "#__codelineno-15-75" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队首出队操作 */< / span >
< a id = "__codelineno-15-76" name = "__codelineno-15-76" href = "#__codelineno-15-76" > < / a > < span class = "w" > < / span > < span class = "nx" > pollFirst< / span > < span class = "p" > ()< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-77" name = "__codelineno-15-77" href = "#__codelineno-15-77" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-78" name = "__codelineno-15-78" href = "#__codelineno-15-78" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-79" name = "__codelineno-15-79" href = "#__codelineno-15-79" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-80" name = "__codelineno-15-80" href = "#__codelineno-15-80" > < / a > < span class = "w" > < / span > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > value< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "p" > .< / span > < span class = "nx" > val< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 存储尾结点值< / span >
< a id = "__codelineno-15-81" name = "__codelineno-15-81" href = "#__codelineno-15-81" > < / a > < span class = "w" > < / span > < span class = "c1" > // 删除头结点< / span >
< a id = "__codelineno-15-82" name = "__codelineno-15-82" href = "#__codelineno-15-82" > < / a > < span class = "w" > < / span > < span class = "kd" > let< / span > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > ListNode< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "p" > .< / span > < span class = "nx" > next< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-83" name = "__codelineno-15-83" href = "#__codelineno-15-83" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "nx" > temp< / span > < span class = "w" > < / span > < span class = "o" > !==< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-84" name = "__codelineno-15-84" href = "#__codelineno-15-84" > < / a > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "p" > .< / span > < span class = "nx" > prev< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-85" name = "__codelineno-15-85" href = "#__codelineno-15-85" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "p" > .< / span > < span class = "nx" > next< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-86" name = "__codelineno-15-86" href = "#__codelineno-15-86" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-87" name = "__codelineno-15-87" href = "#__codelineno-15-87" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 更新头结点< / span >
< a id = "__codelineno-15-88" name = "__codelineno-15-88" href = "#__codelineno-15-88" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "o" > --< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-89" name = "__codelineno-15-89" href = "#__codelineno-15-89" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "nx" > value< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-90" name = "__codelineno-15-90" href = "#__codelineno-15-90" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-91" name = "__codelineno-15-91" href = "#__codelineno-15-91" > < / a >
< a id = "__codelineno-15-92" name = "__codelineno-15-92" href = "#__codelineno-15-92" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 访问队尾元素 */< / span >
< a id = "__codelineno-15-93" name = "__codelineno-15-93" href = "#__codelineno-15-93" > < / a > < span class = "w" > < / span > < span class = "nx" > peekLast< / span > < span class = "p" > ()< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-94" name = "__codelineno-15-94" href = "#__codelineno-15-94" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "w" > < / span > < span class = "o" > ?< / span > < span class = "w" > < / span > < span class = "nx" > null< / span > < span class = "w" > < / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > this.rear.val< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-95" name = "__codelineno-15-95" href = "#__codelineno-15-95" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-96" name = "__codelineno-15-96" href = "#__codelineno-15-96" > < / a >
< a id = "__codelineno-15-97" name = "__codelineno-15-97" href = "#__codelineno-15-97" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 访问队首元素 */< / span >
< a id = "__codelineno-15-98" name = "__codelineno-15-98" href = "#__codelineno-15-98" > < / a > < span class = "w" > < / span > < span class = "nx" > peekFirst< / span > < span class = "p" > ()< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-99" name = "__codelineno-15-99" href = "#__codelineno-15-99" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "w" > < / span > < span class = "o" > ?< / span > < span class = "w" > < / span > < span class = "nx" > null< / span > < span class = "w" > < / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > this.front.val< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-100" name = "__codelineno-15-100" href = "#__codelineno-15-100" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-101" name = "__codelineno-15-101" href = "#__codelineno-15-101" > < / a >
< a id = "__codelineno-15-102" name = "__codelineno-15-102" href = "#__codelineno-15-102" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 获取双向队列的长度 */< / span >
< a id = "__codelineno-15-103" name = "__codelineno-15-103" href = "#__codelineno-15-103" > < / a > < span class = "w" > < / span > < span class = "nx" > size< / span > < span class = "p" > ()< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-104" name = "__codelineno-15-104" href = "#__codelineno-15-104" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-105" name = "__codelineno-15-105" href = "#__codelineno-15-105" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-106" name = "__codelineno-15-106" href = "#__codelineno-15-106" > < / a >
< a id = "__codelineno-15-107" name = "__codelineno-15-107" href = "#__codelineno-15-107" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 判断双向队列是否为空 */< / span >
< a id = "__codelineno-15-108" name = "__codelineno-15-108" href = "#__codelineno-15-108" > < / a > < span class = "w" > < / span > < span class = "nx" > isEmpty< / span > < span class = "p" > ()< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > boolean< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-109" name = "__codelineno-15-109" href = "#__codelineno-15-109" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > len< / span > < span class = "w" > < / span > < span class = "o" > ===< / span > < span class = "w" > < / span > < span class = "mf" > 0< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-110" name = "__codelineno-15-110" href = "#__codelineno-15-110" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-111" name = "__codelineno-15-111" href = "#__codelineno-15-111" > < / a >
< a id = "__codelineno-15-112" name = "__codelineno-15-112" href = "#__codelineno-15-112" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 打印双向队列 */< / span >
< a id = "__codelineno-15-113" name = "__codelineno-15-113" href = "#__codelineno-15-113" > < / a > < span class = "w" > < / span > < span class = "nx" > print< / span > < span class = "p" > ()< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "ow" > void< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-114" name = "__codelineno-15-114" href = "#__codelineno-15-114" > < / a > < span class = "w" > < / span > < span class = "kd" > const< / span > < span class = "w" > < / span > < span class = "nx" > arr< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > number< / span > < span class = "p" > []< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "p" > [];< / span >
< a id = "__codelineno-15-115" name = "__codelineno-15-115" href = "#__codelineno-15-115" > < / a > < span class = "w" > < / span > < span class = "kd" > let< / span > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "o" > :< / span > < span class = "w" > < / span > < span class = "kt" > ListNode< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "nx" > front< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-116" name = "__codelineno-15-116" href = "#__codelineno-15-116" > < / a > < span class = "w" > < / span > < span class = "k" > while< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "nx" > temp< / span > < span class = "w" > < / span > < span class = "o" > !==< / span > < span class = "w" > < / span > < span class = "kc" > null< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-15-117" name = "__codelineno-15-117" href = "#__codelineno-15-117" > < / a > < span class = "w" > < / span > < span class = "nx" > arr< / span > < span class = "p" > .< / span > < span class = "nx" > push< / span > < span class = "p" > (< / span > < span class = "nx" > temp< / span > < span class = "p" > .< / span > < span class = "nx" > val< / span > < span class = "p" > );< / span >
< a id = "__codelineno-15-118" name = "__codelineno-15-118" href = "#__codelineno-15-118" > < / a > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "nx" > temp< / span > < span class = "p" > .< / span > < span class = "nx" > next< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-15-119" name = "__codelineno-15-119" href = "#__codelineno-15-119" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-120" name = "__codelineno-15-120" href = "#__codelineno-15-120" > < / a > < span class = "w" > < / span > < span class = "nx" > console< / span > < span class = "p" > .< / span > < span class = "nx" > log< / span > < span class = "p" > (< / span > < span class = "s2" > " [" < / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "nx" > arr< / span > < span class = "p" > .< / span > < span class = "nx" > join< / span > < span class = "p" > (< / span > < span class = "s2" > " , " < / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "s2" > " ]" < / span > < span class = "p" > );< / span >
< a id = "__codelineno-15-121" name = "__codelineno-15-121" href = "#__codelineno-15-121" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-15-122" name = "__codelineno-15-122" href = "#__codelineno-15-122" > < / a > < span class = "p" > }< / span >
< / code > < / pre > < / div >
< / div >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > linkedlist_deque.c< / span > < pre > < span > < / span > < code > < a id = "__codelineno-16-1" name = "__codelineno-16-1" href = "#__codelineno-16-1" > < / a >
< / code > < / pre > < / div >
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< div class = "highlight" > < span class = "filename" > linkedlist_deque.cs< / span > < pre > < span > < / span > < code > < a id = "__codelineno-17-1" name = "__codelineno-17-1" href = "#__codelineno-17-1" > < / a > < span class = "na" > [class]< / span > < span class = "p" > {< / span > < span class = "n" > ListNode< / span > < span class = "p" > }< / span > < span class = "o" > -< / span > < span class = "p" > [< / span > < span class = "n" > func< / span > < span class = "p" > ]{}< / span >
< a id = "__codelineno-17-2" name = "__codelineno-17-2" href = "#__codelineno-17-2" > < / a >
< a id = "__codelineno-17-3" name = "__codelineno-17-3" href = "#__codelineno-17-3" > < / a > < span class = "na" > [class]< / span > < span class = "p" > {< / span > < span class = "n" > LinkedListDeque< / span > < span class = "p" > }< / span > < span class = "o" > -< / span > < span class = "p" > [< / span > < span class = "n" > func< / span > < span class = "p" > ]{}< / span >
< / code > < / pre > < / div >
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< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > linkedlist_deque.swift< / span > < pre > < span > < / span > < code > < a id = "__codelineno-18-1" name = "__codelineno-18-1" href = "#__codelineno-18-1" > < / a >
< / code > < / pre > < / div >
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< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > linkedlist_deque.zig< / span > < pre > < span > < / span > < code > < a id = "__codelineno-19-1" name = "__codelineno-19-1" href = "#__codelineno-19-1" > < / a >
< / code > < / pre > < / div >
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< h3 id = "_2" > 基于数组的实现< a class = "headerlink" href = "#_2" title = "Permanent link" > ¶ < / a > < / h3 >
< p > 与基于数组实现队列类似，我们也可以使用环形数组来实现双向队列。在实现队列的基础上，增加实现“队首入队”和“队尾出队”方法即可。< / p >
< div class = "tabbed-set tabbed-alternate" data-tabs = "4:5" > < input checked = "checked" id = "__tabbed_4_1" name = "__tabbed_4" type = "radio" / > < input id = "__tabbed_4_2" name = "__tabbed_4" type = "radio" / > < input id = "__tabbed_4_3" name = "__tabbed_4" type = "radio" / > < input id = "__tabbed_4_4" name = "__tabbed_4" type = "radio" / > < input id = "__tabbed_4_5" name = "__tabbed_4" type = "radio" / > < div class = "tabbed-labels" > < label for = "__tabbed_4_1" > ArrayDeque< / label > < label for = "__tabbed_4_2" > pushLast()< / label > < label for = "__tabbed_4_3" > pushFirst()< / label > < label for = "__tabbed_4_4" > pollLast()< / label > < label for = "__tabbed_4_5" > pollFirst()< / label > < / div >
< div class = "tabbed-content" >
< div class = "tabbed-block" >
< p > < img alt = "array_deque" src = "../deque.assets/array_deque.png" / > < / p >
< / div >
< div class = "tabbed-block" >
< p > < img alt = "array_deque_push_last" src = "../deque.assets/array_deque_push_last.png" / > < / p >
< / div >
< div class = "tabbed-block" >
< p > < img alt = "array_deque_push_first" src = "../deque.assets/array_deque_push_first.png" / > < / p >
< / div >
< div class = "tabbed-block" >
< p > < img alt = "array_deque_poll_last" src = "../deque.assets/array_deque_poll_last.png" / > < / p >
< / div >
< div class = "tabbed-block" >
< p > < img alt = "array_deque_poll_first" src = "../deque.assets/array_deque_poll_first.png" / > < / p >
< / div >
< / div >
< / div >
< p > 以下是具体实现代码。< / p >
< div class = "tabbed-set tabbed-alternate" data-tabs = "5:10" > < input checked = "checked" id = "__tabbed_5_1" name = "__tabbed_5" type = "radio" / > < input id = "__tabbed_5_2" name = "__tabbed_5" type = "radio" / > < input id = "__tabbed_5_3" name = "__tabbed_5" type = "radio" / > < input id = "__tabbed_5_4" name = "__tabbed_5" type = "radio" / > < input id = "__tabbed_5_5" name = "__tabbed_5" type = "radio" / > < input id = "__tabbed_5_6" name = "__tabbed_5" type = "radio" / > < input id = "__tabbed_5_7" name = "__tabbed_5" type = "radio" / > < input id = "__tabbed_5_8" name = "__tabbed_5" type = "radio" / > < input id = "__tabbed_5_9" name = "__tabbed_5" type = "radio" / > < input id = "__tabbed_5_10" name = "__tabbed_5" type = "radio" / > < div class = "tabbed-labels" > < label for = "__tabbed_5_1" > Java< / label > < label for = "__tabbed_5_2" > C++< / label > < label for = "__tabbed_5_3" > Python< / label > < label for = "__tabbed_5_4" > Go< / label > < label for = "__tabbed_5_5" > JavaScript< / label > < label for = "__tabbed_5_6" > TypeScript< / label > < label for = "__tabbed_5_7" > C< / label > < label for = "__tabbed_5_8" > C#< / label > < label for = "__tabbed_5_9" > Swift< / label > < label for = "__tabbed_5_10" > Zig< / label > < / div >
< div class = "tabbed-content" >
< div class = "tabbed-block" >
< div class = "highlight" > < span class = "filename" > array_deque.java< / span > < pre > < span > < / span > < code > < a id = "__codelineno-20-1" name = "__codelineno-20-1" href = "#__codelineno-20-1" > < / a > < span class = "cm" > /* 基于环形数组实现的双向队列 */< / span >
< a id = "__codelineno-20-2" name = "__codelineno-20-2" href = "#__codelineno-20-2" > < / a > < span class = "kd" > class< / span > < span class = "nc" > ArrayDeque< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-3" name = "__codelineno-20-3" href = "#__codelineno-20-3" > < / a > < span class = "w" > < / span > < span class = "kd" > private< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "o" > []< / span > < span class = "w" > < / span > < span class = "n" > nums< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 用于存储双向队列元素的数组< / span >
< a id = "__codelineno-20-4" name = "__codelineno-20-4" href = "#__codelineno-20-4" > < / a > < span class = "w" > < / span > < span class = "kd" > private< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 队首指针，指向队首元素< / span >
< a id = "__codelineno-20-5" name = "__codelineno-20-5" href = "#__codelineno-20-5" > < / a > < span class = "w" > < / span > < span class = "kd" > private< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > queSize< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "c1" > // 双向队列长度< / span >
< a id = "__codelineno-20-6" name = "__codelineno-20-6" href = "#__codelineno-20-6" > < / a >
< a id = "__codelineno-20-7" name = "__codelineno-20-7" href = "#__codelineno-20-7" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 构造方法 */< / span >
< a id = "__codelineno-20-8" name = "__codelineno-20-8" href = "#__codelineno-20-8" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "nf" > ArrayDeque< / span > < span class = "p" > (< / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > capacity< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-9" name = "__codelineno-20-9" href = "#__codelineno-20-9" > < / a > < span class = "w" > < / span > < span class = "k" > this< / span > < span class = "p" > .< / span > < span class = "na" > nums< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > new< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "o" > [< / span > < span class = "n" > capacity< / span > < span class = "o" > ]< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-10" name = "__codelineno-20-10" href = "#__codelineno-20-10" > < / a > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > queSize< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "mi" > 0< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-11" name = "__codelineno-20-11" href = "#__codelineno-20-11" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-12" name = "__codelineno-20-12" href = "#__codelineno-20-12" > < / a >
< a id = "__codelineno-20-13" name = "__codelineno-20-13" href = "#__codelineno-20-13" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 获取双向队列的容量 */< / span >
< a id = "__codelineno-20-14" name = "__codelineno-20-14" href = "#__codelineno-20-14" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "nf" > capacity< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-15" name = "__codelineno-20-15" href = "#__codelineno-20-15" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > nums< / span > < span class = "p" > .< / span > < span class = "na" > length< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-16" name = "__codelineno-20-16" href = "#__codelineno-20-16" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-17" name = "__codelineno-20-17" href = "#__codelineno-20-17" > < / a >
< a id = "__codelineno-20-18" name = "__codelineno-20-18" href = "#__codelineno-20-18" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 获取双向队列的长度 */< / span >
< a id = "__codelineno-20-19" name = "__codelineno-20-19" href = "#__codelineno-20-19" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "nf" > size< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-20" name = "__codelineno-20-20" href = "#__codelineno-20-20" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > queSize< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-21" name = "__codelineno-20-21" href = "#__codelineno-20-21" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-22" name = "__codelineno-20-22" href = "#__codelineno-20-22" > < / a >
< a id = "__codelineno-20-23" name = "__codelineno-20-23" href = "#__codelineno-20-23" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 判断双向队列是否为空 */< / span >
< a id = "__codelineno-20-24" name = "__codelineno-20-24" href = "#__codelineno-20-24" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > boolean< / span > < span class = "w" > < / span > < span class = "nf" > isEmpty< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-25" name = "__codelineno-20-25" href = "#__codelineno-20-25" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > queSize< / span > < span class = "w" > < / span > < span class = "o" > ==< / span > < span class = "w" > < / span > < span class = "mi" > 0< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-26" name = "__codelineno-20-26" href = "#__codelineno-20-26" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-27" name = "__codelineno-20-27" href = "#__codelineno-20-27" > < / a >
< a id = "__codelineno-20-28" name = "__codelineno-20-28" href = "#__codelineno-20-28" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 计算环形数组索引 */< / span >
< a id = "__codelineno-20-29" name = "__codelineno-20-29" href = "#__codelineno-20-29" > < / a > < span class = "w" > < / span > < span class = "kd" > private< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "nf" > index< / span > < span class = "p" > (< / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > i< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-30" name = "__codelineno-20-30" href = "#__codelineno-20-30" > < / a > < span class = "w" > < / span > < span class = "c1" > // 通过取余操作实现数组首尾相连< / span >
< a id = "__codelineno-20-31" name = "__codelineno-20-31" href = "#__codelineno-20-31" > < / a > < span class = "w" > < / span > < span class = "c1" > // 当 i 越过数组尾部后，回到头部< / span >
< a id = "__codelineno-20-32" name = "__codelineno-20-32" href = "#__codelineno-20-32" > < / a > < span class = "w" > < / span > < span class = "c1" > // 当 i 越过数组头部后，回到尾部< / span >
< a id = "__codelineno-20-33" name = "__codelineno-20-33" href = "#__codelineno-20-33" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "n" > i< / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "n" > capacity< / span > < span class = "p" > ())< / span > < span class = "w" > < / span > < span class = "o" > %< / span > < span class = "w" > < / span > < span class = "n" > capacity< / span > < span class = "p" > ();< / span >
< a id = "__codelineno-20-34" name = "__codelineno-20-34" href = "#__codelineno-20-34" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-35" name = "__codelineno-20-35" href = "#__codelineno-20-35" > < / a >
< a id = "__codelineno-20-36" name = "__codelineno-20-36" href = "#__codelineno-20-36" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队首入队 */< / span >
< a id = "__codelineno-20-37" name = "__codelineno-20-37" href = "#__codelineno-20-37" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > void< / span > < span class = "w" > < / span > < span class = "nf" > pushFirst< / span > < span class = "p" > (< / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > num< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-38" name = "__codelineno-20-38" href = "#__codelineno-20-38" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "n" > queSize< / span > < span class = "w" > < / span > < span class = "o" > ==< / span > < span class = "w" > < / span > < span class = "n" > capacity< / span > < span class = "p" > ())< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-39" name = "__codelineno-20-39" href = "#__codelineno-20-39" > < / a > < span class = "w" > < / span > < span class = "n" > System< / span > < span class = "p" > .< / span > < span class = "na" > out< / span > < span class = "p" > .< / span > < span class = "na" > println< / span > < span class = "p" > (< / span > < span class = "s" > " 双向队列已满" < / span > < span class = "p" > );< / span >
< a id = "__codelineno-20-40" name = "__codelineno-20-40" href = "#__codelineno-20-40" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-41" name = "__codelineno-20-41" href = "#__codelineno-20-41" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-42" name = "__codelineno-20-42" href = "#__codelineno-20-42" > < / a > < span class = "w" > < / span > < span class = "c1" > // 队首指针向左移动一位< / span >
< a id = "__codelineno-20-43" name = "__codelineno-20-43" href = "#__codelineno-20-43" > < / a > < span class = "w" > < / span > < span class = "c1" > // 通过取余操作，实现 front 越过数组头部后回到尾部< / span >
< a id = "__codelineno-20-44" name = "__codelineno-20-44" href = "#__codelineno-20-44" > < / a > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > index< / span > < span class = "p" > (< / span > < span class = "n" > front< / span > < span class = "w" > < / span > < span class = "o" > -< / span > < span class = "w" > < / span > < span class = "mi" > 1< / span > < span class = "p" > );< / span >
< a id = "__codelineno-20-45" name = "__codelineno-20-45" href = "#__codelineno-20-45" > < / a > < span class = "w" > < / span > < span class = "c1" > // 将 num 添加至队首< / span >
< a id = "__codelineno-20-46" name = "__codelineno-20-46" href = "#__codelineno-20-46" > < / a > < span class = "w" > < / span > < span class = "n" > nums< / span > < span class = "o" > [< / span > < span class = "n" > front< / span > < span class = "o" > ]< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > num< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-47" name = "__codelineno-20-47" href = "#__codelineno-20-47" > < / a > < span class = "w" > < / span > < span class = "n" > queSize< / span > < span class = "o" > ++< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-48" name = "__codelineno-20-48" href = "#__codelineno-20-48" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-49" name = "__codelineno-20-49" href = "#__codelineno-20-49" > < / a >
< a id = "__codelineno-20-50" name = "__codelineno-20-50" href = "#__codelineno-20-50" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队尾入队 */< / span >
< a id = "__codelineno-20-51" name = "__codelineno-20-51" href = "#__codelineno-20-51" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > void< / span > < span class = "w" > < / span > < span class = "nf" > pushLast< / span > < span class = "p" > (< / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > num< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-52" name = "__codelineno-20-52" href = "#__codelineno-20-52" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "n" > queSize< / span > < span class = "w" > < / span > < span class = "o" > ==< / span > < span class = "w" > < / span > < span class = "n" > capacity< / span > < span class = "p" > ())< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-53" name = "__codelineno-20-53" href = "#__codelineno-20-53" > < / a > < span class = "w" > < / span > < span class = "n" > System< / span > < span class = "p" > .< / span > < span class = "na" > out< / span > < span class = "p" > .< / span > < span class = "na" > println< / span > < span class = "p" > (< / span > < span class = "s" > " 双向队列已满" < / span > < span class = "p" > );< / span >
< a id = "__codelineno-20-54" name = "__codelineno-20-54" href = "#__codelineno-20-54" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-55" name = "__codelineno-20-55" href = "#__codelineno-20-55" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-56" name = "__codelineno-20-56" href = "#__codelineno-20-56" > < / a > < span class = "w" > < / span > < span class = "c1" > // 计算尾指针，指向队尾索引 + 1< / span >
< a id = "__codelineno-20-57" name = "__codelineno-20-57" href = "#__codelineno-20-57" > < / a > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > rear< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > index< / span > < span class = "p" > (< / span > < span class = "n" > front< / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "n" > queSize< / span > < span class = "p" > );< / span >
< a id = "__codelineno-20-58" name = "__codelineno-20-58" href = "#__codelineno-20-58" > < / a > < span class = "w" > < / span > < span class = "c1" > // 将 num 添加至队尾< / span >
< a id = "__codelineno-20-59" name = "__codelineno-20-59" href = "#__codelineno-20-59" > < / a > < span class = "w" > < / span > < span class = "n" > nums< / span > < span class = "o" > [< / span > < span class = "n" > rear< / span > < span class = "o" > ]< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > num< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-60" name = "__codelineno-20-60" href = "#__codelineno-20-60" > < / a > < span class = "w" > < / span > < span class = "n" > queSize< / span > < span class = "o" > ++< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-61" name = "__codelineno-20-61" href = "#__codelineno-20-61" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-62" name = "__codelineno-20-62" href = "#__codelineno-20-62" > < / a >
< a id = "__codelineno-20-63" name = "__codelineno-20-63" href = "#__codelineno-20-63" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队首出队 */< / span >
< a id = "__codelineno-20-64" name = "__codelineno-20-64" href = "#__codelineno-20-64" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "nf" > pollFirst< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-65" name = "__codelineno-20-65" href = "#__codelineno-20-65" > < / a > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > num< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > peekFirst< / span > < span class = "p" > ();< / span >
< a id = "__codelineno-20-66" name = "__codelineno-20-66" href = "#__codelineno-20-66" > < / a > < span class = "w" > < / span > < span class = "c1" > // 队首指针向后移动一位< / span >
< a id = "__codelineno-20-67" name = "__codelineno-20-67" href = "#__codelineno-20-67" > < / a > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > index< / span > < span class = "p" > (< / span > < span class = "n" > front< / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "mi" > 1< / span > < span class = "p" > );< / span >
< a id = "__codelineno-20-68" name = "__codelineno-20-68" href = "#__codelineno-20-68" > < / a > < span class = "w" > < / span > < span class = "n" > queSize< / span > < span class = "o" > --< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-69" name = "__codelineno-20-69" href = "#__codelineno-20-69" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > num< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-70" name = "__codelineno-20-70" href = "#__codelineno-20-70" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-71" name = "__codelineno-20-71" href = "#__codelineno-20-71" > < / a >
< a id = "__codelineno-20-72" name = "__codelineno-20-72" href = "#__codelineno-20-72" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 队尾出队 */< / span >
< a id = "__codelineno-20-73" name = "__codelineno-20-73" href = "#__codelineno-20-73" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "nf" > pollLast< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-74" name = "__codelineno-20-74" href = "#__codelineno-20-74" > < / a > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > num< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > peekLast< / span > < span class = "p" > ();< / span >
< a id = "__codelineno-20-75" name = "__codelineno-20-75" href = "#__codelineno-20-75" > < / a > < span class = "w" > < / span > < span class = "n" > queSize< / span > < span class = "o" > --< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-76" name = "__codelineno-20-76" href = "#__codelineno-20-76" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > num< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-77" name = "__codelineno-20-77" href = "#__codelineno-20-77" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-78" name = "__codelineno-20-78" href = "#__codelineno-20-78" > < / a >
< a id = "__codelineno-20-79" name = "__codelineno-20-79" href = "#__codelineno-20-79" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 访问队首元素 */< / span >
< a id = "__codelineno-20-80" name = "__codelineno-20-80" href = "#__codelineno-20-80" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "nf" > peekFirst< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-81" name = "__codelineno-20-81" href = "#__codelineno-20-81" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "n" > isEmpty< / span > < span class = "p" > ())< / span >
< a id = "__codelineno-20-82" name = "__codelineno-20-82" href = "#__codelineno-20-82" > < / a > < span class = "w" > < / span > < span class = "k" > throw< / span > < span class = "w" > < / span > < span class = "k" > new< / span > < span class = "w" > < / span > < span class = "n" > EmptyStackException< / span > < span class = "p" > ();< / span >
< a id = "__codelineno-20-83" name = "__codelineno-20-83" href = "#__codelineno-20-83" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > nums< / span > < span class = "o" > [< / span > < span class = "n" > front< / span > < span class = "o" > ]< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-84" name = "__codelineno-20-84" href = "#__codelineno-20-84" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-85" name = "__codelineno-20-85" href = "#__codelineno-20-85" > < / a >
< a id = "__codelineno-20-86" name = "__codelineno-20-86" href = "#__codelineno-20-86" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 访问队尾元素 */< / span >
< a id = "__codelineno-20-87" name = "__codelineno-20-87" href = "#__codelineno-20-87" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "nf" > peekLast< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-88" name = "__codelineno-20-88" href = "#__codelineno-20-88" > < / a > < span class = "w" > < / span > < span class = "k" > if< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "n" > isEmpty< / span > < span class = "p" > ())< / span >
< a id = "__codelineno-20-89" name = "__codelineno-20-89" href = "#__codelineno-20-89" > < / a > < span class = "w" > < / span > < span class = "k" > throw< / span > < span class = "w" > < / span > < span class = "k" > new< / span > < span class = "w" > < / span > < span class = "n" > EmptyStackException< / span > < span class = "p" > ();< / span >
< a id = "__codelineno-20-90" name = "__codelineno-20-90" href = "#__codelineno-20-90" > < / a > < span class = "w" > < / span > < span class = "c1" > // 计算尾元素索引< / span >
< a id = "__codelineno-20-91" name = "__codelineno-20-91" href = "#__codelineno-20-91" > < / a > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > last< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > index< / span > < span class = "p" > (< / span > < span class = "n" > front< / span > < span class = "w" > < / span > < span class = "o" > +< / span > < span class = "w" > < / span > < span class = "n" > queSize< / span > < span class = "w" > < / span > < span class = "o" > -< / span > < span class = "w" > < / span > < span class = "mi" > 1< / span > < span class = "p" > );< / span >
< a id = "__codelineno-20-92" name = "__codelineno-20-92" href = "#__codelineno-20-92" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > nums< / span > < span class = "o" > [< / span > < span class = "n" > last< / span > < span class = "o" > ]< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-93" name = "__codelineno-20-93" href = "#__codelineno-20-93" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-94" name = "__codelineno-20-94" href = "#__codelineno-20-94" > < / a >
< a id = "__codelineno-20-95" name = "__codelineno-20-95" href = "#__codelineno-20-95" > < / a > < span class = "w" > < / span > < span class = "cm" > /* 返回数组用于打印 */< / span >
< a id = "__codelineno-20-96" name = "__codelineno-20-96" href = "#__codelineno-20-96" > < / a > < span class = "w" > < / span > < span class = "kd" > public< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "o" > []< / span > < span class = "w" > < / span > < span class = "nf" > toArray< / span > < span class = "p" > ()< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-97" name = "__codelineno-20-97" href = "#__codelineno-20-97" > < / a > < span class = "w" > < / span > < span class = "c1" > // 仅转换有效长度范围内的列表元素< / span >
< a id = "__codelineno-20-98" name = "__codelineno-20-98" href = "#__codelineno-20-98" > < / a > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "o" > []< / span > < span class = "w" > < / span > < span class = "n" > res< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "k" > new< / span > < span class = "w" > < / span > < span class = "kt" > int< / span > < span class = "o" > [< / span > < span class = "n" > queSize< / span > < span class = "o" > ]< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-99" name = "__codelineno-20-99" href = "#__codelineno-20-99" > < / a > < span class = "w" > < / span > < span class = "k" > for< / span > < span class = "w" > < / span > < span class = "p" > (< / span > < span class = "kt" > int< / span > < span class = "w" > < / span > < span class = "n" > i< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "mi" > 0< / span > < span class = "p" > ,< / span > < span class = "w" > < / span > < span class = "n" > j< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > front< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "n" > i< / span > < span class = "w" > < / span > < span class = "o" > < < / span > < span class = "w" > < / span > < span class = "n" > queSize< / span > < span class = "p" > ;< / span > < span class = "w" > < / span > < span class = "n" > i< / span > < span class = "o" > ++< / span > < span class = "p" > ,< / span > < span class = "w" > < / span > < span class = "n" > j< / span > < span class = "o" > ++< / span > < span class = "p" > )< / span > < span class = "w" > < / span > < span class = "p" > {< / span >
< a id = "__codelineno-20-100" name = "__codelineno-20-100" href = "#__codelineno-20-100" > < / a > < span class = "w" > < / span > < span class = "n" > res< / span > < span class = "o" > [< / span > < span class = "n" > i< / span > < span class = "o" > ]< / span > < span class = "w" > < / span > < span class = "o" > =< / span > < span class = "w" > < / span > < span class = "n" > nums< / span > < span class = "o" > [< / span > < span class = "n" > index< / span > < span class = "p" > (< / span > < span class = "n" > j< / span > < span class = "p" > )< / span > < span class = "o" > ]< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-101" name = "__codelineno-20-101" href = "#__codelineno-20-101" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-102" name = "__codelineno-20-102" href = "#__codelineno-20-102" > < / a > < span class = "w" > < / span > < span class = "k" > return< / span > < span class = "w" > < / span > < span class = "n" > res< / span > < span class = "p" > ;< / span >
< a id = "__codelineno-20-103" name = "__codelineno-20-103" href = "#__codelineno-20-103" > < / a > < span class = "w" > < / span > < span class = "p" > }< / span >
< a id = "__codelineno-20-104" name = "__codelineno-20-104" href = "#__codelineno-20-104" > < / a > < span class = "p" > }< / span >
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