【题目】

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?

【题意】

【思路】

【代码】

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