leetcode

Posted 2021-01-07 chsobin

1. Two Sum

【题目】https://leetcode.com/problems/two-sum/description/

【思路】将数组 利用 map 处理 即可

【代码】

 1 class Solution {
 2 public:
 3     vector<int> twoSum(vector<int>& nums, int target) {
 4         // 哈希表存储 值->下标 的映射
 5         unordered_map<int, int> indices;
 6         
 7         for (int i = 0; i < nums.size(); i++)
 8         {
 9             int temp = target - nums[i];
10             if (indices.find(temp) != indices.end() && indices[temp] != i)
11             {
12                 return vector<int> {indices[temp], i};
13             }
14             indices.emplace(nums[i], i);
15         }
16     }
17 };

C++

 1 class Solution {
 2     public int[] twoSum(int[] nums, int target) {
 3         Map<Integer, Integer> indeces = new HashMap<>();
 4         for(int i=0;i<nums.length;++i) {
 5             int temp = target - nums[i];
 6             if(indeces.containsKey(temp)) {
 7                 return new int[] {indeces.get(temp), i};
 8             }
 9             indeces.put(nums[i], i);
10         }
11         return null;
12     }
13 }

Java

【get】

C++中 HashMap 的使用

https://blog.csdn.net/charles1e/article/details/52042066