dsa-competitive-programming/leetcode/lc1/onePass.cpp

public:
	vector<int> twoSum(vector<int>& nums, int target){
		unordered_map<int,int>hash;
		for(int i=0;i<nums.size();++i){
			int complement = target - nums[i];
			if(hash.find(complement) != hash.end(){
					return {hash[complement],i};
			hash[nums[i]] = i;
			
		       }
		}
	}