106.NYOJ--SEARCH--素数环

//NYOJ--SEARCH--素数环#include<iostream>#include<cstring>using namespace std;int mark[21],arr[21],n;int judgeNum(int);void dfs(int);int main(){//freopen("input.txt","r",stdin);int count=0;while(cin>>n &&n!=0){count++;cout<<"Case "<<count<<":"<<endl;memset(arr,0,sizeof(mark));memset(mark,0,sizeof(mark));arr[0]=1;if(n%2==0 || n==1){dfs(0);}else{cout<<"No Answer\n";}}return 0;}int judgeNum(int num){for(int i=2;i*i<=num;++i){if(num%i==0){return 0;}}return 1;}void dfs(int th_num){if(th_num==n-1){if(judgeNum(arr[th_num]+1)){cout<<"1";for(int i=1;i<n;++i){cout<<" "<<arr[i];}cout<<endl;}}for(int i=2;i<=n;++i){if(!mark[i] &&judgeNum(i+arr[th_num])){mark[i]=1;arr[th_num+1]=i;dfs(th_num+1);mark[i]=0;}}}