寻找数组中唯一只出现1次的数

一个数组中除开唯一一个元素只出现一次，其余的元素均出现三次。

 

位运算，看不明白，留着以后看吧。

 

#include <stdio.h>
#include <algorithm>
using namespace std;
#define maxn 1000
int a[maxn],n;

int main()
{    
    while(scanf("%d",&n), n)
    {
        int one = 0, two = 0, three = 0;
        for(int i=0; i<n; i++)
        {
            scanf("%d",&a[i]);
            three = two & a[i];
            two = two | one & a[i];
            one = one | a[i];
            two = two & ~three;
            one = one & ~three;
        }      
        printf("%d\n",one);
    }
    return 0;
}