Cod sursa(job #688976)
Utilizator | Data | 23 februarie 2012 23:49:25 | |
---|---|---|---|
Problema | Factorial | Scor | 40 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.32 kb |
#include <fstream>
using namespace std;
int main ()
{
ifstream fin ("fact.in");
ofstream fout ("fact.out");
long s=0,n,p,x,k;
fin>>p;
if (p==0) {fout<<"1"; return 0;}
for (n=5;s<p;n+=5)
{x=n;
k=0;
while (x%5==0){k++;x=x/5;}
s=s+k;
}
n=n-5;
if (s==p) fout<<n;
else fout<<"-1";
return 0;
}