LeetCode 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?

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