Single Number【只出现一次的数字】

Question:

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?

Answer(Cpp):

class Solution {
public:
    int singleNumber(vector<int>& nums) {
        int num=0;
        for(int i=0;i<nums.size();i++){
            num^=nums[i];
        }
        return num;
    }
};

很神奇的解法！