single-number

原文地址：https://www.jianshu.com/p/19449c705838

时间限制：1秒 空间限制：32768K

题目描述

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?

我的代码

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

运行时间：7ms
占用内存：476k