Faktorial,permutasi dan Kombinasi C++

#include<iostream.h>
#include<conio.h>
int faktorial (int n)
{

if (n==0){
return (1);}
else {
return (n*faktorial(n-1));
}
}
int permutasi (int n,int r){
int perm;
perm=faktorial(n)/(faktorial(n-r));
return perm;
}
int kombinasi (int n,int r){
int kom;
kom=faktorial(n)/(faktorial(n-r)*faktorial(r));
return kom;
}
int main()
{
int n,r;
cout<<"\t\t==>>|FAKTORIAL,PERMUTASI DAN KOMBINASI|<<=="<<endl;
cout<<"=>input nilai n : ";cin>>n;
cout<<"=>Input nilai r : ";cin>>r;
system("cls");
cout<<"\t\t==>>|FAKTORIAL,PERMUTASI DAN KOMBINASI|<<=="<<endl;
cout<<"==>>Hasil"<<endl;
cout<<"\tNilai n : "<<n<<endl;
cout<<"\tNilai r : "<<r<<endl;
cout<<"\tNilai faktorial : "<<faktorial(n)<<endl;
cout<<"\tNilai Permutasi : "<<permutasi(n,r)<<endl;
cout<<"\tNilai kombinasi : "<<kombinasi(n,r);
getch();
}