# HDU OJ 1016 Prime Ring Problem

```#include <iostream>
#include <stdio.h>
using namespace std;
int n,map[30],vis[30];
void dfs(int s[30], int x, int vis[30])
{
int i, t, j,flag;
if(x==n-1)
{
flag=0;
t=s[x]+1;
for(j=2;j<t;j++)
{
if(t%j==0)
{
flag=1;
break;
}
}
if(flag)
return ;
for(i=0;i<n;i++)
{
if(i!=n-1)
printf("%d ",s[i]);
else
printf("%d\n",s[i]);
}
return ;
}
for(i=1;i<=n;i++)
{
if(!vis[i])
{
t=i+s[x];
flag=0;
for(j=2;j<t;j++)
{
if(t%j==0)
{
flag=1;
break;
}
}
if(flag==0)
{
vis[i]=1;
s[x+1]=i;
dfs(s,x+1,vis);
vis[i]=0;
}
}
}
}
int main()
{
int num=0;
while(scanf("%d",&n)!=EOF)
{
num++;
memset(map,0,sizeof(map));
memset(vis,0,sizeof(vis));
vis[1]=1;
map[0]=1;
printf("Case %d:\n",num);
dfs(map,0,vis);
printf("\n");
}
return 0;
}```

## HDU 1016 Prime Ring Problem 题解

Problem Description A ring is compose of n circles as shown in diagram. Put natural number 1, 2, ..., n into each circle separately, and the sum of numbers in two adjacent circles should be a prime. Note: the number of first circle should always be 1

## 【dfs】hdu 1016 Prime Ring Problem

[dfs]hdu 1016 Prime Ring Problem 题目链接 刚开始接触搜索,先来一道基本题目练练手. 注意对树的深度进行dfs dfs过程中注意回退!!! 素数提前打表判断快一些 参考代码 /*Author:Hacker_vision*/ #include<bits/stdc++.h> #define clr(k,v) memset(k,v,sizeof(k)) using namespace std; const int _max=1e3+10;//素数打表 int n,pr

## hdu 1016 Prime Ring Problem (简单DFS)

Prime Ring Problem Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 25700    Accepted Submission(s): 11453 Problem Description A ring is compose of n circles as shown in diagram. Put natural numb

## [ACM] 1016 Prime Ring Problem （深度优先搜索）

Prime Ring Problem Problem Description A ring is compose of n circles as shown in diagram. Put natural number 1, 2, ..., n into each circle separately, and the sum of numbers in two adjacent circles should be a prime. Note: the number of first circle

## hdu 1016 Prime Ring Problem DFS解法 纪念我在杭电的第一百题

Prime Ring Problem Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 29577    Accepted Submission(s): 13188 Problem Description A ring is compose of n circles as shown in diagram. Put natural num