Leetcode 1——twosum

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.

Example:

Given nums = [2, 7, 11, 15], target = 9,

Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1].

Solution：

public class Solution {
    public int[] twoSum(int[] nums, int target) {
        int[] result=new int[2];
        for(int i=0;i<nums.length-1;i++){
            for(int j=i+1;j<nums.length;j++)
            {
                if(target==nums[i]+nums[j]){
                    result[0]=i;
                    result[1]=j;
                }
        }
    }
        return result;
}

    }

一个简单的java程序，两次for循环，时间复杂度是O（n^2），空间复杂度为O（1）。