Cod sursa(job #1273481)
Utilizator | Data | 22 noiembrie 2014 15:24:33 | |
---|---|---|---|
Problema | Factorial | Scor | 35 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.62 kb |
#include <fstream>
using namespace std;
ifstream f("fact.in");
ofstream g("fact.out");
int functie(int N)
{
int k=5,S=0;
while (k<=N)
{
S+=N/k;
k*=5;
}
return S;
}
int main()
{
int n,st=1,dr=20000000,x,p,m=1,nr=-1,a;
f>>p;
if(p==0) g<<1<<'\n';
else
{
while(st<=dr)
{
x=(st+dr)/2;
a=functie(x);
if(a==p)
{
nr=x-x%5;
break;
}
else if(a<p) st=x+1;
else dr=x-1;
}
g<<nr;
}
return 0;
}