Cod sursa(job #831907)
Utilizator | Sacaci Cosmin cosmins97 | Data | 9 decembrie 2012 14:21:32 |
---|---|---|---|
Problema | Factorial | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.66 kb |
#include <climits>
#include <fstream>
using namespace std;
ifstream fin("fact.in");
ofstream fout("fact.out");
int main()
{
int p,m,i=1,j=LONG_MAX,ok=0,x,k;
fin>>p;
if(p==0)fout<<"1";
while(i<=j&&ok==0)
{
m=(i+j)/2;
x=5;k=0;
while(x<=m)
{
k=k+m/x;
x=x*5;
}
if(k==p)ok=1;
else if(k>p)j=m-1;
else i=m+1;
}
if(ok==0)fout<<"-1";
else
{
while(m%5!=0)m--;
fout<<m;
}
fin.close();
fout.close();
return 0;
}