LeetCode: 136 Single Number(easy)

题目：

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：

class Solution {
public:
    int singleNumber(vector<int>& nums) {
        int result = 0;
        for (auto c : nums)
            result ^= c;
        return result;
    }
};