1. 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) { vector<int> re; for(int i = 0;i<=nums.size();i++){ for(int j = i +1;j<nums.size();j++){ if(nums[j]==target -nums[i]) { re.push_back(i); re.push_back(j); return re; } } } //return re; } };