Cod sursa(job #172905)

Utilizator ivanov.georgeIvanov George Bogdan ivanov.george Data 6 aprilie 2008 21:37:19
Problema Factorial Scor 40
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.69 kb
//FACTORIAL

#include<iostream.h>
#include<fstream.h>
long putere5(int k){
     long p=1;
     for(int i = 1;i<=k;i++,p*=5);
     return p;
}
int main(){
    long n,p,i,j,k;
    ifstream in("fact.in");
    ofstream out("fact.out");
    in>>p;
    //cin>>p;
    n = 0;i = 0;
    if(p==0)
            out<<"1"<<endl;
    else{
    while(i<p){
                n+=5;
                i++;
                for(j = 2;j<=20;j++)
                      if(n%putere5(j)==0) i++;
                      else break;
                
    }
    if(i>p) 
            cout<<"-1"<<endl;
    else
            out<<n<<endl;
    }
    //getch();
    in.close();
    out.close();
    return 0;
}