Cod sursa(job #3185608)
Utilizator | Ionescu Mihail mihail_11 | Data | 19 decembrie 2023 19:00:45 |
---|---|---|---|
Problema | Factorial | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.74 kb |
#include <iostream>
#include <fstream>
using namespace std;
int main()
{
long long int P,N,contor=0,i,st,dr,mid,ans,ver;
ifstream fin("fact.in");
ofstream fout("fact.out");
st=1;
dr=5e8;
fin>>P;
while(st<=dr)
{
mid=(st+dr)/2;
contor=0;
for(i=5;i<=mid;i*=5)
{
contor=contor+mid/i;
}
if(contor>=P)
{
ans=mid;
dr=mid-1;
}
else
{
st=mid+1;
}
}
ver=ans;
contor=0;
for(i=5;i<=ver;i*=5)
{
contor=contor+ver/i;
}
if(P==contor)
{
fout<<ans;
}
else
{
fout<<-1;
}
return 0;
}