Program Pascal - Deret Bilangan Segitiga & Fibonacci Menggunakan Fungsi Rekursif

Source Code:

program Der_Bil_Sgtg_Fibo_REK;
uses crt;
var pil:char;

function fibonacci(x:integer):integer;
begin
        if(x=1) then fibonacci:=0 else
        if(x=2) then fibonacci:=1 else
        fibonacci:=fibonacci(x-1)+fibonacci(x-2);
end;

function segitiga (n:integer):real;
var i:integer;
begin
  if n > 0 then
    begin
     segitiga:= segitiga(n-1)+n;
    end;
end;

procedure menu1;
  var n,i: integer;
  begin
   clrscr;
    writeln;
    writeln('>> Deret Bilangan Segitiga <<');
    writeln;
    write('     Input Bilangan : '); readln(n);
    writeln;
    write('     Hasil          : ');
     for i:=1 to n do
        write(segitiga(i):2:0,' ');
    readkey;
end;

procedure menu2;
  var n,i : integer;
  begin

    clrscr;
    writeln;
    writeln('>> Deret Bilangan Fibonacci <<');
    writeln;
    write  (' Masukkan Banyak Deret = ');readln(n);
    writeln;
    writeln('        Hasilnya : ');
    writeln;
    for i:=1 to n do
    write('  ',fibonacci(i),' ');
    readkey;
  end;

begin
  repeat
    clrscr;
    writeln;
    writeln('>> PROGRAM BIL. SEGITIGA & FIBONACCI REKURSIF <<');
    writeln;
    writeln('      ------>>>>> Menu Utama <<<<<--------   ');
    writeln;
    writeln('   [1] Bilangan Segitiga');
    writeln('   [2] Bilangan Fibonacci');
    writeln('   [0] Exit Program');
    writeln;
    write  ('Pilihan : ');pil:=readkey;
    case pil of
      '1':menu1;
      '2':menu2;
    end;
  until
    pil='0';
end.