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）。