Cod sursa(job #719481)
Utilizator | Data | 21 martie 2012 20:35:36 | |
---|---|---|---|
Problema | Factorial | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.48 kb |
#include <fstream>
using namespace std;
long long x;
int p;
long long nrzero(long long x)
{
long long i,rez=0;
for (i=5;i<=x;i*=5)
rez+=x/i;
return rez;
}
long long ff (int x)
{
long long i,pas = 1LL<<40;
for (i=0;pas!=0;pas/=2)
if (nrzero(i+pas)<p)
i+=pas;
return i+1;
}
int main()
{
ifstream f("fact.in");
ofstream g("fact.out");
f>>p;
x=ff(p);
if (nrzero(x)==p)
g<<x;
else g<<"-1";
return 0;
}