function factorial(n: integer): longint;
begin
if (n = 0) then
factorial := 1
else
factorial := n * factorial(n – 1);
end;

function permutasi(a, r:integer):real;
begin
if (a=0) then
permutasi := 1
else
permutasi := factorial(a)/factorial(a-r);
end;

var x, y: integer;
begin
writeln(‘Program Permutasi’;
writeln;
write(‘Berapa banyak n: ‘;
readln(x);
write(‘Jumlah yang dipilih (r): ‘;
readln(y);
writeln;
writeln(‘ permutasi = ‘, permutasi(x, y):3:2);
readln;
end.