1. Two Sum

题目：

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 thesame element twice.

Example:

Given nums = [2, 7, 11, 15], target = 9,Because nums[0] + nums[1] = 2 + 7 = 9,return [0, 1]. 我的代码：
class Solution {    public int[] twoSum(int[] nums, int target) {        int[] des = new int[2];        int ans=1;        for(int i=0;i<nums.length;i++)        {            if(ans==0){                break;            }            for(int j=i+1;j<nums.length;j++)            {                ans=nums[i]+nums[j];                     if(ans==target){                    des[0]=i;                    des[1]=j;                    ans=0;                        }            }        }        return des;    }}