Cod sursa(job #1936971)
Utilizator | Dobricean Ionut Dobricean_Ioan | Data | 23 martie 2017 16:29:54 |
---|---|---|---|
Problema | Factorial | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.46 kb |
#include <fstream>
using namespace std;
ifstream cin("fact.in");
ofstream cout("fact.out");
int m5fact(int n){
int sum=0;
while(n>=5){
sum+=n/5;
n/=5;
}
return sum;
}
int cautb(int n){
int pas=1<<28,r=0;
while(pas!=0){
if(m5fact(r+pas)<n){
r+=pas;
}
pas/=2;
}
if(m5fact(r+1)==n){return r+1;}
return -1;
}
int main()
{
int p;
cin>>p;
cout<<cautb(p);
return 0;
}