DOUBLE LINK LIST PASCAL

uses crt;

type

   Pnode = ^node;

   node = record

          info:char;

          before,next:Pnode;

end;

double = object

   awal,baru,akhir:Pnode;

   procedure initial;

   procedure tambah_awal(p:char);

   procedure tambah_akhir(p:char);

   procedure cetak;

End;

procedure double.initial;

begin

   awal:=nil;

   akhir:=nil;

end;

procedure double.tambah_awal(p:char);

begin

   new(baru);

   baru^.info:=p;

   baru^.before:=nil;

   if awal=nil then

   begin

      awal:=baru;

      akhir:=baru;

   end

   else

   begin

      baru^.next:=awal;

      awal^.before:=baru;

      awal:=baru;

   end;

end;

procedure double.tambah_akhir(p:char);

begin

   new(baru);

   baru^.info:=p;

   baru^.next:=nil;

   if awal=nil then

   begin

      awal:=baru;

      akhir:=baru;

   end

   else

   begin

      baru^.before:=akhir;

      akhir^.next:=baru;

      akhir:=baru;

   end;

end;

procedure double.cetak;

var

   bantu:pnode;

   c:char;

begin

   bantu:=awal;

   repeat

   if (bantu =awal)  then

      textcolor(lightgreen);

      if (bantu =akhir) then

         textcolor(lightred);

         write(bantu^.info,'-');

         repeat

            c:=readkey;

         until ord(c) in[75,77,27];

         case  ord(c) of

            75: if bantu <>awal then bantu:=bantu^.before;

            77: if bantu <> akhir then bantu:=bantu^.next;

         end;

      textcolor(white);

   until c=#27;

end;

var

    list:double;

    k:char;

begin

   clrscr;

   textcolor(white);

   writeln('    -Program Double Linked List-');

   repeat

      write('Karakter : ');

      k:=readkey;

      if not(k in [#13,#27]) then

         list.tambah_akhir(upcase(k));

         writeln(k);

   until k=#27;writeln;

   list.cetak;

end.

Posted in: PROGRAM PASCAL