Prime number Determination

Time limit:2000/1000 MS (java/others) Memory limit:65536/32768 K (java/others)
Total submission (s): 91615 Accepted Submission (s): 32165

Problem description for an expression n^2+n+41, when n takes an integer value in the (x, y) range (including x, y) ( -39<=x<y<=50), the value of the expression is determined to be a prime number.

Input data has multiple groups, one row per group, consisting of two integers, x, y, and when x=0,y=0, indicates that the input ends and the row is not processed.

Output for each given range of values, if the value of the expression is a prime number, outputs "OK", otherwise output "Sorry", each set of output in one row.

Sample Input

0 10 0

Sample Output

Ok

#include <stdio.h>
#include <math.h>
int f (int s)
{
 int i,j=0,k=0;
 //printf ("%d\n", s);
 for (i=2;i<=sqrt (s); i++)
 if (s%i==0)
 j++;
 //else k++;
 if (j==0)
 return 1;
 else
 return 0;
}
Main ()
{
 int x,y,i,j,a,b,c,k;
while (scanf ("%d%d", &x,&y)!=eof)
  {
   if (x==0&&y==0)
   break;
 j=0;
 k=0;
 c=y-x+1;
// printf ("%d\n", c);
 for (i=x;i<=y;i++)
 {
 a=i*i+i+41;
 b=f (a);
 //printf ("%d", b);
 if (b==0)
 k++;
 //{
 // printf ("sorry\n");
 // break;
 //}
 
  if (b==1)
   j + +;
 }
// printf ("%d%d\n", j,k);
 if (j==c)
 printf ("ok\n");
 else printf ("sorry\n");
 }
 return 0; 
}

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Prime number Determination