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 }