leetcode-1

class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
    unordered_map <int,int> map;
    for(int i=0;i<nums.size();i++){
        int s = target - nums[i];
        auto it = map.find(s);
        if(it!=map.end()){
        return {it->second,i};
        }
        map.insert(pair<int,int>(nums[i],i));
    }


    return {};
    }
};