和为S的两个数字

class Solution {
public:
    vector<int> findNumbersWithSum(vector<int>& nums, int target) {
        unordered_set<int> hashtable;
        for(auto i:nums)
        {
            if(hashtable.count(target-i))   return vector<int>{i,target-i};
            hashtable.insert(i);
        }
    }
};