leetcode 136. Single Number

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?

代码：

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

总结：利用异或操作，两个相同的数会抵消掉。