T001兩數之和

題目描述

思路

將target-i放入unordered_map.

代碼

class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        unordered_map<int,int> m;
        vector <int> result;
        for(int i = 0;i < nums.size();i++)
        {
            if(m.find(nums[i]) == m.end())
            {
                m[target - nums[i]] = i; 
            }
            else
            {
                result.push_back(m[nums[i]]);
                result.push_back(i);
                break;
            }
        }
        return result;
    }
};