136. Single Number

Given an array of integers, every element appears twice except for one. Find that single one.

Note:
Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?

一个数组里每个数都出现两次，除了一个数只出现一次。想要找出这个只出现过一次的数，用异或^符可以轻松找到，代码如下：

public class Solution {    public int singleNumber(int[] nums) {        int result = 0;        for (int i = 0; i < nums.length; i++) {            result ^= nums[i];        }        return result;    }}