leetcode 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].

这题考查基本算法实现，关于给定一个数组，找出两个数字，进行分析两个数字之和为最后一个数字，那么仅仅需要进行2重循环进行遍历即可

class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        vector<int> res;
        for(int i=0;i<nums.size()-1;i++){
            for(int j=i+1;j<nums.size();j++){
                if(nums[i]+nums[j]==target) {
                    res.push_back(i);
                    res.push_back(j);
                    return res;
                }
            }
        }
        return res;
    }
};