Single Number

Description:

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?

Code:

1  int singleNumber(vector<int>& nums) {

2         int result = 0;

3         for (int i = 0; i < nums.size(); ++i)

4         {

5             result^=nums[i];

6         }

7         return result;

8     }