From ac8d0bcfebc305ce285ad6018762191ed3bbc53f Mon Sep 17 00:00:00 2001 From: krahets Date: Thu, 10 Nov 2022 03:40:57 +0800 Subject: [PATCH] Add the chapter of stack and queue. --- .../chapter_array_and_linkedlist/list.java | 16 +-- .../chapter_stack_and_queue/array_queue.java | 113 ++++++++++++++++++ .../chapter_stack_and_queue/array_stack.java | 77 ++++++++++++ codes/java/chapter_stack_and_queue/deque.java | 37 ++++++ .../linkedlist_queue.java | 75 ++++++++++++ .../linkedlist_stack.java | 72 +++++++++++ codes/java/chapter_stack_and_queue/queue.java | 33 +++++ codes/java/chapter_stack_and_queue/stack.java | 33 +++++ docs/index.md | 1 + mkdocs.yml | 5 + 10 files changed, 454 insertions(+), 8 deletions(-) create mode 100644 codes/java/chapter_stack_and_queue/array_queue.java create mode 100644 codes/java/chapter_stack_and_queue/array_stack.java create mode 100644 codes/java/chapter_stack_and_queue/deque.java create mode 100644 codes/java/chapter_stack_and_queue/linkedlist_queue.java create mode 100644 codes/java/chapter_stack_and_queue/linkedlist_stack.java create mode 100644 codes/java/chapter_stack_and_queue/queue.java create mode 100644 codes/java/chapter_stack_and_queue/stack.java diff --git a/codes/java/chapter_array_and_linkedlist/list.java b/codes/java/chapter_array_and_linkedlist/list.java index 1a478ea07..94391f175 100644 --- a/codes/java/chapter_array_and_linkedlist/list.java +++ b/codes/java/chapter_array_and_linkedlist/list.java @@ -8,7 +8,7 @@ public class list { // 注意数组的元素类型是 int[] 的包装类 Integer[] Integer[] numbers = new Integer[] { 1, 3, 2, 5, 4 }; List list = new ArrayList<>(Arrays.asList(numbers)); - System.out.println("列表 list = " + Arrays.toString(list.toArray())); + System.out.println("列表 list = " + list); /* 访问元素 */ int num = list.get(1); @@ -16,11 +16,11 @@ public class list { /* 更新元素 */ list.set(1, 0); - System.out.println("将索引 1 处的元素更新为 0 ，得到 list = " + Arrays.toString(list.toArray())); + System.out.println("将索引 1 处的元素更新为 0 ，得到 list = " + list); /* 清空列表 */ list.clear(); - System.out.println("清空列表后 list = " + Arrays.toString(list.toArray())); + System.out.println("清空列表后 list = " + list); /* 尾部添加元素 */ list.add(1); @@ -28,15 +28,15 @@ public class list { list.add(2); list.add(5); list.add(4); - System.out.println("添加元素后 list = " + Arrays.toString(list.toArray())); + System.out.println("添加元素后 list = " + list); /* 中间插入元素 */ list.add(3, 6); - System.out.println("在索引 3 处插入数字 6 ，得到 list = " + Arrays.toString(list.toArray())); + System.out.println("在索引 3 处插入数字 6 ，得到 list = " + list); /* 删除元素 */ list.remove(3); - System.out.println("删除索引 3 处的元素，得到 list = " + Arrays.toString(list.toArray())); + System.out.println("删除索引 3 处的元素，得到 list = " + list); /* 通过索引遍历列表 */ int count = 0; @@ -53,10 +53,10 @@ public class list { /* 拼接两个列表 */ List list1 = new ArrayList<>(Arrays.asList(new Integer[] { 6, 8, 7, 10, 9 })); list.addAll(list1); - System.out.println("将列表 list1 拼接到 list 之后，得到 list = " + Arrays.toString(list.toArray())); + System.out.println("将列表 list1 拼接到 list 之后，得到 list = " + list); /* 排序列表 */ Collections.sort(list); - System.out.println("排序列表后 list = " + Arrays.toString(list.toArray())); + System.out.println("排序列表后 list = " + list); } } diff --git a/codes/java/chapter_stack_and_queue/array_queue.java b/codes/java/chapter_stack_and_queue/array_queue.java new file mode 100644 index 000000000..8f455f457 --- /dev/null +++ b/codes/java/chapter_stack_and_queue/array_queue.java @@ -0,0 +1,113 @@ +package chapter_stack_and_queue; + +import java.util.*; + +/* 基于环形数组实现的队列 */ +class ArrayQueue { + int[] nums; // 用于存储队列元素的数组 + int size = 0; // 队列长度（即元素个数） + int front = 0; // 头指针，指向队首 + int rear = 0; // 尾指针，指向队尾 + 1 + + public ArrayQueue(int capacity) { + // 初始化数组 + nums = new int[capacity]; + } + + /* 获取队列的容量 */ + public int capacity() { + return nums.length; + } + + /* 获取队列的长度 */ + public int size() { + int capacity = capacity(); + // 由于将数组看作为环形，可能 rear < front ，因此需要取余数 + return (capacity + rear - front) % capacity; + } + + /* 判断队列是否为空 */ + public boolean isEmpty() { + return rear - front == 0; + } + + /* 入队 */ + public void offer(int num) { + if (size() == capacity()) { + System.out.println("队列已满"); + return; + } + // 尾结点后添加 num + nums[rear] = num; + // 尾指针向后移动一位，越过尾部后返回到数组头部 + rear = (rear + 1) % capacity(); + } + + /* 出队 */ + public int poll() { + // 删除头节点 + if (isEmpty()) + throw new EmptyStackException(); + int num = nums[front]; + // 队头指针向后移动，越过尾部后返回到数组头部 + front = (front + 1) % capacity(); + return num; + } + + /* 访问队首元素 */ + public int peek() { + // 删除头节点 + if (isEmpty()) + throw new EmptyStackException(); + return nums[front]; + } + + public int[] toArray() { + int size = size(); + int capacity = capacity(); + // 仅转换有效长度范围内的列表元素 + int[] arr = new int[size]; + for (int i = 0, j = front; i < size; i++, j++) { + arr[i] = nums[j % capacity]; + } + return arr; + } +} + +public class array_queue { + public static void main(String[] args) { + /* 初始化队列 */ + int capacity = 10; + ArrayQueue queue = new ArrayQueue(capacity); + + /* 元素入队 */ + queue.offer(1); + queue.offer(3); + queue.offer(2); + queue.offer(5); + queue.offer(4); + System.out.println("队列 queue = " + Arrays.toString(queue.toArray())); + + /* 访问队首元素 */ + int peek = queue.peek(); + System.out.println("队首元素 peek = " + peek); + + /* 元素出队 */ + int poll = queue.poll(); + System.out.println("出队元素 poll = " + poll + "，出队后 queue = " + Arrays.toString(queue.toArray())); + + /* 获取队列的长度 */ + int size = queue.size(); + System.out.println("队列长度 size = " + size); + + /* 判断队列是否为空 */ + boolean isEmpty = queue.isEmpty(); + + /* 测试环形数组 */ + for (int i = 0; i < 10; i++) { + queue.offer(i); + queue.poll(); + System.out.println("第 " + i + " 轮入队+出队后 queue = " + Arrays.toString(queue.toArray())); + } + } +} diff --git a/codes/java/chapter_stack_and_queue/array_stack.java b/codes/java/chapter_stack_and_queue/array_stack.java new file mode 100644 index 000000000..5f2b74081 --- /dev/null +++ b/codes/java/chapter_stack_and_queue/array_stack.java @@ -0,0 +1,77 @@ +package chapter_stack_and_queue; + +import java.util.*; + +/* 基于数组实现的栈 */ +class ArrayStack { + ArrayList list; + public ArrayStack() { + // 初始化列表（动态数组） + list = new ArrayList<>(); + } + + /* 获取栈的长度 */ + public int size() { + return list.size(); + } + + /* 判断栈是否为空 */ + public boolean isEmpty() { + return size() == 0; + } + + /* 入栈 */ + public void push(int num) { + list.add(num); + } + + /* 出栈 */ + public int pop() { + return list.remove(size() - 1); + } + + /* 访问栈顶元素 */ + public int peek() { + return list.get(size() - 1); + } + + /* 访问索引 index 处元素 */ + public int get(int index) { + return list.get(index); + } + + /* 将 List 转化为 Array 并返回 */ + public Object[] toArray() { + return list.toArray(); + } +} + +public class array_stack { + public static void main(String[] args) { + /* 初始化栈 */ + ArrayStack stack = new ArrayStack(); + + /* 元素入栈 */ + stack.push(1); + stack.push(3); + stack.push(2); + stack.push(5); + stack.push(4); + System.out.println("栈 stack = " + Arrays.toString(stack.toArray())); + + /* 访问栈顶元素 */ + int peek = stack.peek(); + System.out.println("栈顶元素 peek = " + peek); + + /* 元素出栈 */ + int pop = stack.pop(); + System.out.println("出栈元素 pop = " + pop + "，出栈后 stack = " + Arrays.toString(stack.toArray())); + + /* 获取栈的长度 */ + int size = stack.size(); + System.out.println("栈的长度 size = " + size); + + /* 判断是否为空 */ + boolean isEmpty = stack.isEmpty(); + } +} diff --git a/codes/java/chapter_stack_and_queue/deque.java b/codes/java/chapter_stack_and_queue/deque.java new file mode 100644 index 000000000..837eb90a5 --- /dev/null +++ b/codes/java/chapter_stack_and_queue/deque.java @@ -0,0 +1,37 @@ +package chapter_stack_and_queue; + +import java.util.*; + +public class deque { + public static void main(String[] args) { + /* 初始化队列 */ + Deque deque = new LinkedList<>(); + + /* 元素入队 */ + deque.offerLast(2); + deque.offerLast(5); + deque.offerLast(4); + deque.offerFirst(3); + deque.offerFirst(1); + System.out.println("队列 deque = " + deque); + + /* 访问队首元素 */ + int peekFirst = deque.peekFirst(); + System.out.println("队首元素 peekFirst = " + peekFirst); + int peekLast = deque.peekLast(); + System.out.println("队尾元素 peekLast = " + peekLast); + + /* 元素出队 */ + int pollFirst = deque.pollFirst(); + System.out.println("队首出队元素 pollFirst = " + pollFirst + "，队首出队后 deque = " + deque); + int pollLast = deque.pollLast(); + System.out.println("队尾出队元素 pollLast = " + pollLast + "，队尾出队后 deque = " + deque); + + /* 获取队列的长度 */ + int size = deque.size(); + System.out.println("队列长度 size = " + size); + + /* 判断队列是否为空 */ + boolean isEmpty = deque.isEmpty(); + } +} diff --git a/codes/java/chapter_stack_and_queue/linkedlist_queue.java b/codes/java/chapter_stack_and_queue/linkedlist_queue.java new file mode 100644 index 000000000..4bbb10f3c --- /dev/null +++ b/codes/java/chapter_stack_and_queue/linkedlist_queue.java @@ -0,0 +1,75 @@ +package chapter_stack_and_queue; + +import java.util.*; + +/* 基于链表实现的队列 */ +class LinkedListQueue { + LinkedList list; + + public LinkedListQueue() { + // 初始化链表 + list = new LinkedList<>(); + } + + /* 获取队列的长度 */ + public int size() { + return list.size(); + } + + /* 判断队列是否为空 */ + public boolean isEmpty() { + return list.size() == 0; + } + + /* 入队 */ + public void offer(int num) { + // 尾结点后添加 num + list.addLast(num); + } + + /* 出队 */ + public int poll() { + // 删除头节点 + return list.removeFirst(); + } + + /* 访问队首元素 */ + public int peek() { + return list.getFirst(); + } + + /* 将 List 转化为 Array 并返回 */ + public Object[] toArray() { + return list.toArray(); + } +} + +public class linkedlist_queue { + public static void main(String[] args) { + /* 初始化队列 */ + LinkedListQueue queue = new LinkedListQueue(); + + /* 元素入队 */ + queue.offer(1); + queue.offer(3); + queue.offer(2); + queue.offer(5); + queue.offer(4); + System.out.println("队列 queue = " + Arrays.toString(queue.toArray())); + + /* 访问队首元素 */ + int peek = queue.peek(); + System.out.println("队首元素 peek = " + peek); + + /* 元素出队 */ + int poll = queue.poll(); + System.out.println("出队元素 poll = " + poll + "，出队后 queue = " + Arrays.toString(queue.toArray())); + + /* 获取队列的长度 */ + int size = queue.size(); + System.out.println("队列长度 size = " + size); + + /* 判断队列是否为空 */ + boolean isEmpty = queue.isEmpty(); + } +} diff --git a/codes/java/chapter_stack_and_queue/linkedlist_stack.java b/codes/java/chapter_stack_and_queue/linkedlist_stack.java new file mode 100644 index 000000000..bf626f6f8 --- /dev/null +++ b/codes/java/chapter_stack_and_queue/linkedlist_stack.java @@ -0,0 +1,72 @@ +package chapter_stack_and_queue; + +import java.util.*; + +/* 基于链表实现的栈 */ +class LinkedListStack { + LinkedList list; + public LinkedListStack() { + // 初始化链表 + list = new LinkedList<>(); + } + + /* 获取栈的长度 */ + public int size() { + return list.size(); + } + + /* 判断栈是否为空 */ + public boolean isEmpty() { + return size() == 0; + } + + /* 入栈 */ + public void push(int num) { + list.addLast(num); + } + + /* 出栈 */ + public int pop() { + return list.removeLast(); + } + + /* 访问栈顶元素 */ + public int peek() { + return list.getLast(); + } + + /* 将 List 转化为 Array 并返回 */ + public Object[] toArray() { + return list.toArray(); + } +} + +public class linkedlist_stack { + public static void main(String[] args) { + /* 初始化栈 */ + LinkedListStack stack = new LinkedListStack(); + + /* 元素入栈 */ + stack.push(1); + stack.push(3); + stack.push(2); + stack.push(5); + stack.push(4); + System.out.println("栈 stack = " + Arrays.toString(stack.toArray())); + + /* 访问栈顶元素 */ + int peek = stack.peek(); + System.out.println("栈顶元素 peek = " + peek); + + /* 元素出栈 */ + int pop = stack.pop(); + System.out.println("出栈元素 pop = " + pop + "，出栈后 stack = " + Arrays.toString(stack.toArray())); + + /* 获取栈的长度 */ + int size = stack.size(); + System.out.println("栈的长度 size = " + size); + + /* 判断是否为空 */ + boolean isEmpty = stack.isEmpty(); + } +} diff --git a/codes/java/chapter_stack_and_queue/queue.java b/codes/java/chapter_stack_and_queue/queue.java new file mode 100644 index 000000000..fecf2b2cd --- /dev/null +++ b/codes/java/chapter_stack_and_queue/queue.java @@ -0,0 +1,33 @@ +package chapter_stack_and_queue; + +import java.util.*; + +public class queue { + public static void main(String[] args) { + /* 初始化队列 */ + Queue queue = new LinkedList<>(); + + /* 元素入队 */ + queue.offer(1); + queue.offer(3); + queue.offer(2); + queue.offer(5); + queue.offer(4); + System.out.println("队列 queue = " + queue); + + /* 访问队首元素 */ + int peek = queue.peek(); + System.out.println("队首元素 peek = " + peek); + + /* 元素出队 */ + int poll = queue.poll(); + System.out.println("出队元素 poll = " + poll + "，出队后 queue = " + queue); + + /* 获取队列的长度 */ + int size = queue.size(); + System.out.println("队列长度 size = " + size); + + /* 判断队列是否为空 */ + boolean isEmpty = queue.isEmpty(); + } +} diff --git a/codes/java/chapter_stack_and_queue/stack.java b/codes/java/chapter_stack_and_queue/stack.java new file mode 100644 index 000000000..f6add4d12 --- /dev/null +++ b/codes/java/chapter_stack_and_queue/stack.java @@ -0,0 +1,33 @@ +package chapter_stack_and_queue; + +import java.util.*; + +public class stack { + public static void main(String[] args) { + /* 初始化栈 */ + Stack stack = new Stack<>(); + + /* 元素入栈 */ + stack.push(1); + stack.push(3); + stack.push(2); + stack.push(5); + stack.push(4); + System.out.println("栈 stack = " + stack); + + /* 访问栈顶元素 */ + int peek = stack.peek(); + System.out.println("栈顶元素 peek = " + peek); + + /* 元素出栈 */ + int pop = stack.pop(); + System.out.println("出栈元素 pop = " + pop + "，出栈后 stack = " + stack); + + /* 获取栈的长度 */ + int size = stack.size(); + System.out.println("栈的长度 size = " + size); + + /* 判断是否为空 */ + boolean isEmpty = stack.isEmpty(); + } +} diff --git a/docs/index.md b/docs/index.md index 9cc991f82..22f426b2a 100644 --- a/docs/index.md +++ b/docs/index.md @@ -21,3 +21,4 @@ TODO | 新增：数据与内存 | 2022-11-05 | | 更新：各章节 Java 代码 | 2022-11-06 | | 更新：列表 Java 代码、配图 | 2022-11-07 | +| 新增：栈与队列 | 2022-11-09 | diff --git a/mkdocs.yml b/mkdocs.yml index e79aedea1..adeaf5273 100644 --- a/mkdocs.yml +++ b/mkdocs.yml @@ -135,5 +135,10 @@ nav: - 链表: chapter_array_and_linkedlist/linked_list.md - 列表: chapter_array_and_linkedlist/list.md - 小结: chapter_array_and_linkedlist/summary.md + - 栈与队列: + - chapter_stack_and_queue/index.md + - 栈: chapter_stack_and_queue/stack.md + - 队列: chapter_stack_and_queue/queue.md + - 小结: chapter_stack_and_queue/summary.md - License: - chapter_license/index.md \ No newline at end of file