[LeetCode] 136. 只出现一次的数字

给定一个整数数组，除了某个元素外其余元素均出现两次。请找出这个只出现一次的元素。

备注：

你的算法应该是一个线性时间复杂度。 你可以不用额外空间来实现它吗？

英文

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?

JAVA

class Solution {
    public int singleNumber(int[] nums) {
        int num = 0;
        for (int n : nums) {
            num ^= n;
        }
        return num;
    }
}