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46 lines
1.6 KiB
Java
46 lines
1.6 KiB
Java
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package chapter_searching;
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import include.*;
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import java.util.*;
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public class hashing_search {
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/* 哈希查找(数组) */
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static int hashingSearch(Map<Integer, Integer> 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.getOrDefault(target, -1);
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}
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/* 哈希查找(链表) */
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static ListNode hashingSearch1(Map<Integer, ListNode> map, int target) {
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// 哈希表的 key: 目标结点值,value: 结点对象
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// 若哈希表中无此 key ,返回 -1
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return map.getOrDefault(target, null);
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}
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public static void main(String[] args) {
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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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Map<Integer, Integer> map = new HashMap<>();
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for (int i = 0; i < nums.length; i++) {
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map.put(nums[i], i); // key: 元素,value: 索引
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}
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int index = hashingSearch(map, target);
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System.out.println("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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Map<Integer, ListNode> map1 = new HashMap<>();
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while (head != null) {
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map1.put(head.val, head); // key: 结点值,value: 结点
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head = head.next;
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}
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ListNode node = hashingSearch1(map1, target);
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System.out.println("目标结点值 3 的对应结点对象为 " + node);
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}
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}
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