hdu-1016

约瑟夫换问题

http://acm.hdu.edu.cn/showproblem.php?pid=1016

#include <stdio.h>
#include <stdlib.h>
#include <algorithm>
#include <string.h>

int n,cas=1,visit[20],result[20]={0,1}; 
int p[]={0,0,1,1,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,0,0,0,0,1,0,1,0,0,0,0,0,1,0,1,0};

void DFS(int pos)
{
    int i;
    if(pos==n && p[result[1]+result[n]])
    {
        printf("%d",result[1]);
        for(i=2;i<=n;i++)
            printf(" %d",result[i]);
        printf("\n");
        return;
    }

    for(i=2;i<=n;i++)
    {
        if(!visit[i] && p[i+result[pos]])
        {
            result[pos+1]=i;
            visit[i]=1;
            DFS(pos+1);
            visit[i]=0;
        }
    }
}

int main()
{
    while(scanf("%d",&n)!=EOF )
    {
        memset(visit,0,sizeof(visit));
        printf("Case %d:\n",cas++);
        if(n%2==0)
            DFS(1);
        printf("\n");
    }
}