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].
时间：O(n^2)、空间：O(1)
public class Solution {
public int[] twoSum(int[] nums, int target) {
for(int first = 0; first < nums.length; ++first) {
for(int second = first + 1; second < nums.length; ++second) {
if(nums[first] + nums[second] == target) {
return new int[] { first, second };
}
}
}
return new int[0];
}
}
原文：http://www.cnblogs.com/YaungOu/p/6718673.html