hello-algo/codes/cpp/chapter_searching/hashing_search.cpp
2022-11-29 02:21:49 +08:00

55 lines
1.5 KiB
C++
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/*
* File: hashing_search.cpp
* Created Time: 2022-11-25
* Author: Krahets (krahets@163.com)
*/
#include "../include/include.hpp"
/* 哈希查找(数组) */
int hashingSearch(unordered_map<int, int> map, int target) {
// 哈希表的 key: 目标元素value: 索引
// 若哈希表中无此 key ,返回 -1
if (map.find(target) == map.end())
return -1;
return map[target];
}
/* 哈希查找(链表) */
ListNode* hashingSearch1(unordered_map<int, ListNode*> map, int target) {
// 哈希表的 key: 目标结点值value: 结点对象
// 若哈希表中无此 key ,返回 nullptr
if (map.find(target) == map.end())
return nullptr;
return map[target];
}
/* Driver Code */
int main() {
int target = 3;
/* 哈希查找(数组) */
vector<int> nums = { 1, 5, 3, 2, 4, 7, 5, 9, 10, 8 };
// 初始化哈希表
unordered_map<int, int> map;
for (int i = 0; i < nums.size(); i++) {
map[nums[i]] = i; // key: 元素value: 索引
}
int index = hashingSearch(map, target);
cout << "目标元素 3 的索引 = " << index << endl;
/* 哈希查找(链表) */
ListNode* head = vecToLinkedList(nums);
// 初始化哈希表
unordered_map<int, ListNode*> map1;
while (head != nullptr) {
map1[head->val] = head; // key: 结点值value: 结点
head = head->next;
}
ListNode* node = hashingSearch1(map1, target);
cout << "目标结点值 3 的对应结点对象为 " << node << endl;
return 0;
}