unit ListUnit;

interface

type
   TMyType = string;
   PListPointer = ^TMyList;
   TMyList = record
      Num: TMyType;
      pNext: PListPointer;
   end;
   TListClass = class
      Counter: Integer;
      pCurrent: PListPointer;
      pFirst: PListPointer;
      procedure Add(const Value: TMyType);
      procedure Next;
      function GetValue: TMyType;
      procedure Delete(const Number: Word);
      constructor Create;
   end;

implementation

{ TStackClass }

procedure TListClass.Add(const Value: TMyType);
var
   Temp: PListPointer;
begin
   New(Temp);
   Temp^.Num := Value;
   Temp^.pNext := pCurrent^.pNext;
   pCurrent^.pNext := Temp;
   Inc(Counter);
end;

constructor TListClass.Create;
var
   Temp: PListPointer;
begin
   New(Temp);
   Temp^.pNext := Temp;
   pCurrent := Temp;
   pFirst := Temp;
   Counter := 0;
end;

procedure TListClass.Delete(const Number: Word);
var
   Temp, Del: PListPointer;
   i: Integer;
begin
   i := 0;
   Temp := pFirst;
   while i < Number - 1 do
   begin
      Temp := Temp^.pNext;
      inc(i);
   end;
   Del := Temp^.pNext;
   Temp.pNext := Temp^.pNext^.pNext;
   Dispose(Del);
   Dec(Counter);
end;

function TListClass.GetValue: TMyType;
begin
   GetValue := pCurrent^.Num;
end;

procedure TListClass.Next;
begin
   pCurrent := pCurrent^.pNext;
end;

end.