HDU 3304 Interesting Yang Yui Triangle Lucas theorem

Enter P N to find out how many of the n+1 lines of the Yang Hui triangle cannot be divisible by P

Lucas theorem: A, B are non-negative integers, p is prime. AB is written in P-system: a=a[n]a[n-1]...a[0],b=b[n]b[n-1]...b[0].
The combined number C (A, B) and C (A[n],b[n]) *c (a[n-1],b[n-1]) *...*c (a[0],b[0]) mod p congruence

That is: Lucas (n,m,p) =c (n%p,m%p) *lucas (n/p,m/p,p), when there is i,b[i]>a[i], the MoD value is 0, so it must be divisible; when for all I,b[i]<=a[i], a[i]!%p!=0, So it must not be divisible.

#include <cstdio>
#include <cmath>
#include <cstring>
using namespace std;

int main ()
{
    int p, n;
    int cas = 1;
    while (scanf ("%d%d", &p, &n)! = EOF)
    {
        if (p ==0 && n ==0) break
            ;
        int sum = 1;
        while (n)
        {
            sum *= n%p+1;
            n/= p;
        }
        printf ("Case%d:%04d\n", cas++, sum%10000);
    }
}