可以直接暴力循环两遍，用一个新的vector存储找的下标。
class Solution { public: vector<int> twoSum(vector<int>& nums, int target) { vector<int> val; for (int i =0; i <= nums.size()-1; i++){ for(int j =i+1; j<= nums.size() -1 ; j++){ if (nums[i] + nums[j] == target){ val.push_back(i); val.push_back(j); } } /*if (val.size()>=1) break;*/ } return val; } };