Cod sursa(job #3138733)
Utilizator | Tragla Matei piertoi | Data | 21 iunie 2023 19:43:21 |
---|---|---|---|
Problema | Factorial | Scor | 0 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.65 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream fin("fact.in");
ofstream fout("fact.out");
int n,p;
int nrZerouri(int n)
{
int p=5,nr=0;
while(p<=n)
{
nr+=n/p;
p*=5;
}
return nr;
}
int main()
{
int st=1,dr=500000000,nr;
fin>>p;
while(st<=dr)
{
int mij=(st+dr)/2;
nr=nrZerouri(mij);
if(nr>p)
dr=mij-1;
else if(nr<p)
st=mij+1;
else
{
fout<<mij-mij%5;
return 0;
}
}
if(p==0)
{
fout<<1
return 0;
}
fout<<-1;
return 0;
}