hdu1016

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

int prime[38]={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}; int visit[21]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; int result[21]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

void print(int* s, int n) { int i; for(i=0;i<n;i++) { if(i) printf(" %d",s[i]); else printf("%d",s[i]); } printf("\n"); }

void dfs(int* s, int* c,int i, int n) { int k; if(!i) { s[0]=1; c[1]=1; dfs(s,c,i+1,n); c[1]=0; } else if(i<n-1) { for(k=2;k<=n;k++) { if(!c[k] && prime[s[i-1]+k]) { s[i]=k; c[k]=1; dfs(s,c,i+1,n); c[k]=0; } } } else if(i==n-1) { for(k=2;k<=n;k++) { if(!c[k] && prime[s[i-1]+k] && prime[k+1]) { s[i]=k; c[k]=1; dfs(s,c,i+1,n); c[k]=0; } } } else if(i==n) { print(s, n); } }

int main(void) { int n,i; i=1; while(scanf("%d", &n)!=EOF) { printf("Case %d:\n",i++); memset(result,0,21); memset(visit,0,21); dfs(result,visit,0,n); printf("\n"); } return 0; }