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/**
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* File: hashing_search.cs
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* Created Time: 2022-12-23
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* Author: haptear (haptear@hotmail.com)
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*/
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namespace hello_algo.chapter_searching;
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public class hashing_search {
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/* 哈希查找(数组) */
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int HashingSearchArray(Dictionary<int, int> map, int target) {
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// 哈希表的 key: 目标元素,value: 索引
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// 若哈希表中无此 key ,返回 -1
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return map.GetValueOrDefault(target, -1);
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}
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/* 哈希查找(链表) */
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ListNode? HashingSearchLinkedList(Dictionary<int, ListNode> map, int target) {
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// 哈希表的 key: 目标节点值,value: 节点对象
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// 若哈希表中无此 key ,返回 null
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return map.GetValueOrDefault(target);
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}
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[Test]
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public void Test() {
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int target = 3;
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/* 哈希查找(数组) */
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int[] nums = [1, 5, 3, 2, 4, 7, 5, 9, 10, 8];
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// 初始化哈希表
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Dictionary<int, int> map = [];
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for (int i = 0; i < nums.Length; i++) {
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map[nums[i]] = i; // key: 元素,value: 索引
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}
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int index = HashingSearchArray(map, target);
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Console.WriteLine("目标元素 3 的索引 = " + index);
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/* 哈希查找(链表) */
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ListNode? head = ListNode.ArrToLinkedList(nums);
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// 初始化哈希表
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Dictionary<int, ListNode> map1 = [];
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while (head != null) {
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map1[head.val] = head; // key: 节点值,value: 节点
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head = head.next;
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}
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ListNode? node = HashingSearchLinkedList(map1, target);
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Console.WriteLine("目标节点值 3 的对应节点对象为 " + node);
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}
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}
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