listy

program List;

{$APPTYPE CONSOLE}

{$R *.res}

uses
  System.SysUtils;

type
    PElement = ^TElement;
    TElement = record
        Data: integer;
        Next: PElement;
    end;

var
    First: PElement;
    Size: integer;
    I: integer;
    Temp: integer;

procedure Push(data: integer);
var
  Current: PElement;
  Temp: PElement;
begin
  if First = nil then
  begin
    new(First);
    First^.Data := data;
    First^.Next := nil;
    exit;
  end;

  Current := First;

  while Current^.Next <> nil do Current := Current^.Next;

  Temp := Current;
  new(Current);
  Current^.Data := data;
  Current^.Next := nil;
  Temp^.Next := Current;
end;

procedure Print();
var
  Current: PElement;
begin
  Current := First;
  while Current <> nil do
  begin
    write(Current^.Data, ' ');
    Current := Current^.Next;
  end;
  writeln;

end;

procedure InsertAfter(index: integer; data: integer);
var
  Current, Temp: PElement;
  I: integer;
begin
  if First = nil then
  begin
    writeln('Lista jest pusta. Nie mozna wstawic elementu');
    exit;
  end;

  Current := First;

  for I := 1 to index do
  begin
    if Current = nil then
    begin
      writeln('Indeks jest za duzy. Nie mozna wstawic elementu.');
      exit;
    end;

    Current := Current^.Next;
  end;

  new(Temp);
  Temp^.Data := data;

  Temp^.Next := Current^.Next;
  Current^.Next := Temp;
end;

procedure DeleteAfter(index: integer);
var
   Current, Temp: PElement;
   I : integer;
begin
    if First = nil then
    begin
      writeln('Lista jest pusta. Nie mozna usunac elementu');
      exit;
    end;

    Current := First;

    for I := 1 to index do
    begin
      if Current = nil then
      begin
        writeln('Indeks jest za duzy. Nie mozna usunac elementu.');
        exit;
      end;

      Current := Current^.Next;
    end;

    if Current^.Next = nil then
    begin
      writeln('Element jeszcze nie zostal dodany. Nie mozna usunac elementu.');
      exit;
    end;

    Temp := Current^.Next^.Next;
    dispose(Current^.Next);
    Current^.Next := Temp;
end;

function Find(data: integer): PElement;
var
  Current: PElement;
begin
  Current := First;
  while Current <> nil do
  begin
    if Current^.Data = data then
    begin
      Result := Current;
      exit;
    end;

    Current := Current^.Next;
  end;
  Result := nil;
end;

begin
  write('Ilosc elementow: ');
  readln(Size);

  for I := 0 to size - 1 do
    begin
      write('a[', I, '] = ');
      readln(Temp);
      Push(Temp);
    end;

  InsertAfter(0, 10);
  Print();
  DeleteAfter(0);
  Print();
  readln;
end.