Hamming Distance(随机算法)

http://acm.hdu.edu.cn/showproblem.php?pid=4712

题意：计算任意两个十六进制的数异或后1的最少个数。

思路：用随机数随机产生两个数作为下标，记录这两个数异或后1的个数，输出1的个数最少是多少。

#include <stdio.h>
#include <algorithm>
#include <time.h>
#include <math.h>

using namespace std;
const int N=100002;
const int INF=1<<29;
int f[N];
int main()
{
    int t;
    scanf("%d",&t);
    while(t--)
    {
        int n,ans = INF;
        scanf("%d",&n);
        for (int i = 0; i < n; i ++)
            scanf("%x",&f[i]);
        srand((unsigned)time(NULL));
        for (int i = 0; i < N*10; i ++)
        {
            int a = rand()%n;
            int b = rand()%n;
            if (a==b)
                continue ;
            int t = f[a]^f[b];
            int temp = __builtin_popcount(t);
            ans = min(ans,temp);
        }
        printf("%d
",ans);
    }
    return 0;
}