Cod sursa(job #1273331)
Utilizator | Data | 22 noiembrie 2014 15:07:07 | |
---|---|---|---|
Problema | Factorial | Scor | 10 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.74 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 st=1,dr=20000000,x,p,m=1,nr,a;
f>>p;
if(p==0) g<<1<<'\n';
else
{
while(st<=dr&&m)
{
x=(st+dr)/2;
a=functie(x);
if(a==p)
{
nr=x-x%5;
m=0;
}
else if(a<p) st=x+1;
else dr=dr-1;
}
if(m==0) g<<nr<<'\n';
else g<<-1<<'\n';
}
return 0;
}