[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?

思路：

这题没什么难度，只要知道异或的操作就可以了

题解：

class Solution 
{
public:
    int singleNumber(int A[], int n) 
    {
        int single = A[0];
        for(int i=1;i<n;i++)
            single = single ^ A[i];
        return single;
    }
};