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)。