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 diff = target - nums[i];

if(Map.find(diff) != Map.end()){

return { Map[diff], i };

}

Map[nums[i]] = i;

}

return {};

}

};