[Leetcode] 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?

利用两个相同的数异或等于0，还有异或交换律。

public class Solution { public int singleNumber(int[] nums) { int num=0; int len=nums.length; while(len>0) {num=num^nums[len-1]; len--; } return num; } }