Multifactorials

ACCEPTED !!! The UVa forum posts contain very handy test cases.. 
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Question: Multifactorials
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#include "iostream.h"
#include "math.h"

long long int max = pow(10, 18);
int primes[1000], pcount;

int isPrime(int n) {
   double sq = sqrt(n);
   for(int i = 2; i <= sq; i++) if(n % i == 0) return 0;
   return 1;
}

void updateFactors(int t, int *pfactorcount) {
   for(int i = 0; i < pcount; i++) {
       int p = primes[i];
       while(t % p == 0) {
           t /= p;
           pfactorcount[p]++;
       }
       if(t == 1) break;
   }
}

long long int multiFactovisors(int n, int k) {
   int stop;
   if(k == 0) stop = n;
   else {
       if(n % k == 0) stop = k;
       else stop = n % k;
   }
   int pfactorcount[1000];
   for(int i = 0; i < 1000; i++) pfactorcount[i] = 0;
   int i = 0;
   while(1) {
       int t = n - k * i;
       updateFactors(t, pfactorcount);
       i++;
       if(t == stop) break;
   }
   long long int prod = 1;
   for(int i = 0; i < pcount; i++) {
       prod *= (pfactorcount[primes[i]] + 1);
       if(prod > max || prod < 1) return 0;
   }
   return prod;
}

int main()
{
   int pindex = 0;
   for(int i = 2; i < 1000; i++) if(isPrime(i)) primes[pindex++] = i;
   pcount = pindex;

   int t;
   cin >> t;
   for(int i = 1; i <= t; i++) {
       char inp[25];
       cin >> inp;
       int n = atoi(inp);
       long long int r;
       if(n <= 0) r = 1;
       else {
           int j;
           for(j = 0; inp[j] != '!'; j++);
           int k = strlen(inp) - j;
           r = multiFactovisors(n, k);
       }
       cout << "Case " << i << ": ";
       if(r > 0) cout << r << endl;
       else cout << "Infinity\n";
   }
   return 0;
}
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