HDU OJ 1016 Prime Ring Problem

#include 
#include 
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