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 r=target-nums[i];
if(map.count(r)) return{map[r],i};
map[nums[i]]=i;
}
return{};
}
};