Two Sum

Given an array of integers, return indices of the two numbers such that they add up to a specific target.

You may assume that each input would have exactly one solution, and you may not use the same element twice.

Example:

Given nums = [2, 7, 11, 15], target = 9,Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1].
class Solution {public:    vector<int> twoSum(vector<int>& nums, int target) {                int first = 0;int second = 0;int size = nums.size();vector<int >  result;                for(first = 0; first < size;first++){        int minus_target = target - (nums.at(first));                for(second = first + 1; second < (size); second++){if(minus_target == (nums.at(second))){        result.push_back(first);        result.push_back(second);        return result;}}         }                return result;}};