LeetCode OJ——Single Number

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(int A[], int n) {
        // Note: The Solution object is instantiated only once and is reused by each test case.
       int res=0;
        int i;
        for(i=0;i<n;i++)
        {
            res=res^A[i];
        }
        return res;
    }
};