杭电 2012

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 int is_prime(int );
 6 int main()
 7 {
 8     int x,y,val;
 9     while (cin>>x>>y && x||y)
10     {
11         int flag = 1;
12         for (int i=x;i<=y;i++)
13         {
14             val = i*i + i +41;
15 /*            flag = flag*is_prime(val);*/
16             if (!is_prime(val))
17             {
18                 flag = 0;
19                 break;
20             }
21         }
22         if (flag)
23         {
24             cout << "OK" << endl;
25         }
26         else
27         {
28             cout << "Sorry" <<endl;
29         }
30     }
31     return 0;
32 }
33 
34 int is_prime(int n) // 质数返回1
35 {
36     if (n<=2)
37     {
38         return 0;
39     }
40     for (int i = 2; i*i <=n; i++)
41     {
42         if (n % i ==0)
43         {
44             return 0;
45         }
46     }
47     return 1;
48 }