mirror of
https://github.com/krahets/hello-algo.git
synced 2024-12-27 01:26:28 +08:00
54 lines
1.5 KiB
C++
54 lines
1.5 KiB
C++
/**
|
||
* 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;
|
||
}
|