HDU2161

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<algorithm>
 4 using namespace std;
 5 const int maxn = 16005;
 6 int vis[maxn];
 7 
 8 void Init()
 9 {
10     memset(vis, 0, sizeof(vis));
11     vis[1] = 1;
12     for(int i = 2; i <= maxn; i++)
13     {
14         for(int j = i+i; j <= maxn; j +=i)
15             vis[j] = 1;
16     }
17     return ;
18 }
19 int main()
20 {
21     Init();
22     int n, kase = 1;
23     while(~scanf("%d", &n))
24     {
25         if(n <= 0) break;
26         if(n == 1 || n == 2)
27         {
28             printf("%d: no\n", kase++);
29             continue;
30         }
31         if(!vis[n]) printf("%d: yes\n", kase++);
32         else printf("%d: no\n", kase++);
33     }
34     return 0;
35 }