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) {
        int result = 0 ;
        for(int i=0;i<n;++i){
             result=result^A[i];
        }
        return result;
    }
};