103_leetcode_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?

1:xor

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