Cod sursa(job #738736)
Utilizator | Data | 21 aprilie 2012 13:35:15 | |
---|---|---|---|
Problema | Factorial | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.51 kb |
#include <fstream>
using namespace std;
ifstream f("fact.in");
ofstream g("fact.out");
long long p,st,dr,m;
long long nr_zero(long long n)
{
long long nr_zero,p;
nr_zero=0;
p=5;
while(p<=n)
{
nr_zero+=n/p;
p=p*5;
}
return nr_zero;
}
int main()
{
f>>p;
st=1;
dr=1000000000;
while(st<dr)
{
m=(st+dr)/2;
if(nr_zero(m)<p)
st=m+1;
else
dr=m;
}
if(nr_zero(st)==p)
g<<st;
else
g<<-1;
f.close();
g.close();
return 0;
}