Einführung in die imperative Programmierung

Forward-Deklaration

program forward;
 uses crt;
   
   var i : integer;
   
   function b(i: integer) : string; 
     forward; 
   
   function a(i: integer) : string;
   begin
   if (i=0) then 
   a:= ''
   else 
   a := b(i-1) + 'a';
   end;
   
   function b(i: integer) : string;
   begin
   if (i=0) then 
   b:= ''
   else 
   b := a(i-1) + 'b';
   end;
BEGIN
   readln(i);
   writeln(a(i));
   
END.