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

使用异或