permutation C++

I am posting this response also includes the results of my exam yesterday as discrete mathematics.

Please know the following is the calculation formula of permutations:

sourcecode:

#include
#include

class per{
public:
masukan();
proses();
private:
int n,r,i;
int faktorn,faktorr;
};

per::masukan(){
cout<<"\t\tProgram Permutasi "< cout<<"http://yt-yusufruli.blogspot.com";
}

int main(){
per x;
x.masukan();
x.proses();

getch();
return 0;
}