delete pics to save space

2.524.cpp

@@ -0,0 +1,50 @@
+#include<cstdio>
+#include<cstring>
+using namespace std;
+bool isp[40],used[20];
+int n,res[20];
+bool ISP(int n)
+{
+	if(n<=1) return 0;
+	for(int i=2;i*i<=n;i++)
+		if(n%i==0) return 0;
+	return 1;
+}
+void dfs(int pos)
+{
+	if(pos>=n)
+	{
+		if(isp[1+res[pos-1]])
+		{
+			printf("1");
+			for(int i=1;i<pos;i++) printf(" %d",res[i]);
+			printf("\n");
+		}
+		return;
+	}
+	for(int i=2;i<=n;i++)
+		if(!used[i]&&isp[res[pos-1]+i])
+		{
+			res[pos]=i;
+			used[i]=1;
+			dfs(pos+1);
+			used[i]=0;
+		}
+} 
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	for(int i=0;i<40;i++) isp[i]=ISP(i);
+	int cnt=0;
+	while(scanf("%d",&n)==1)
+	{
+		if(cnt) printf("\n");
+		printf("Case %d:\n",++cnt);
+		memset(used,0,sizeof(used));
+		res[0]=1;
+		dfs(1);
+	}
+	return 0;
+}