# [1. Two Sum](https://leetcode.com/problems/two-sum/) # 思路 刚开始用暴力匹配,后来看了答案恍然大悟,hash会快很多。 # C++ ``` C++ class Solution { public: vector<int> twoSum(vector<int>& nums, int target) { map<int, int>mp; vector<int>ans; int len = nums.size(); for(int i = 0; i < len; i++){ if( mp.find(target - nums[i]) != mp.end()){ ans.push_back(mp[target - nums[i]]); ans.push_back(i); return ans; } mp[nums[i]] = i; } } }; ```