link list

program LINK_LIST;
uses wincrt;
type addres=^buku;
     buku=record
          nama:string[25];
          alamat:string[100];
          next:addres;
          end;
var
   head,tail,now:addres;
   x:char;

procedure buat;
begin
head:=nil;tail:=nil;
end;

procedure first;
begin
now:=head
end;

procedure setelah;
begin
if now^.next<>nil then
   now:=now^.next;
end;

procedure ubah(var a,b:string);
begin
     now^.nama:=a;
     now^.alamat:=b;
end;

{procedure hapus;
var x:addres;
begin
writeln('masukkan nama yang akan dihapus');readln(now^.nama);
if now^.nama<>head^.nama then
begin
     x:=head;
     while x^.next<>now do
           x:=x^.next;
     x^.next:=now^.next;
end;
 if now^.nama=head^.nama then
head:=head^.next;
dispose(now);
now:=head;
end;}

procedure tambah;
var baru:addres;
begin
new(baru);
write('Masukkan Nama : ');readln(baru^.nama);
write('Masukkan NRP  : ');readln(baru^.alamat);
if head=nil then
  head:=baru
else
   tail^.next:=baru;
   tail:=baru;
   tail^.next:=nil;
end;

procedure tampil;
var bantu:addres;
begin
clrscr;
bantu:=head;
writeln('.: DATA MAHASISWA :.');
writeln('   ____ _________   ');
writeln;
repeat
      writeln('Nama:',bantu^.nama);
      writeln('NRP:',bantu^.alamat);
      writeln;
      bantu:=bantu^.next;
until bantu=nil;

end;

procedure bersih ;
begin
 while head<>nil do
  begin
  now:=head;
  head:=head^.next;
  dispose(now);
  end;
  end;

begin
repeat
clrscr;
writeln('1.Mengisi Buku ');
writeln('2.Melihat Isi Buku');
writeln('3.Membersihkan Daftar buku ');
write('Masukkan Pilihan Anda (keluar alt + F4) : ');readln(x);
writeln;
case x of
'1':
    begin
    tambah;
    end;            
'2':begin
    tampil;
    readln;
    end;
   
{'3':
    begin
   
    tambah;
    end;}

'3':
    begin
    bersih;
    end;

{'5':begin
    first;setelah;hapus;
    end;}
end;
until x=#27;
end.