Cod sursa(job #698127)

Utilizator anamariaaAvram Ana-Maria anamariaa Data 29 februarie 2012 12:29:55
Problema Factorial Scor 20
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.33 kb
Raporteaza aceasta sursa 
#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;
		 s=0;
		 k=0;
		 while (x%5==0){k+=x/5;x=x/5;}
		 s=s+k;
		}
	n=n-5;
	if (s==p) fout<<n;
		else fout<<"-1";
	return 0;
}