unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Addbtn: TButton;
    Memo1: TMemo;
    Label1: TLabel;
    DelBtn: TButton;
    InputdataEdt: TEdit;
    Label2: TLabel;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    procedure FormActivate(Sender: TObject);
    procedure FormKeyPress(Sender: TObject; var Key: Char);
    procedure AddbtnClick(Sender: TObject);
    procedure DelBtnClick(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    function  Fact(num:integer):integer;
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;


implementation

const
     maxsize  = 5;


type
   TStackStructure = record
      items: array[1..maxsize] of string;
      top:integer;
   end;

 var
    stack:TStackStructure;



{$R *.dfm}

function TForm1.Fact(num:integer):integer;
begin
    if num=1 then
       Result:=1
    else
       Result:=num * Fact(num-1);
end;

procedure TForm1.FormActivate(Sender: TObject);
var
   i:integer;
begin
   for i:=1 to maxsize do
      stack.items[i]:='';

   top:=0;
end;

procedure TForm1.FormKeyPress(Sender: TObject; var Key: Char);
begin
    if key=#27 then
       close;
end;

procedure TForm1.AddbtnClick(Sender: TObject);
var
   temp:string;
   i:integer;
begin
     if stack.top = maxsize then
        begin
             memo1.Lines.Add('堆疊已滿');
             abort;
        end;

//將資料加入stack中-S
    inc(stack.top);
    stack.items[stack.top]:= inputdataEdt.Text;
//將資料加入stack中-E

//將stack資料列印出來-S
    temp:='';

    for i:=1 to  stack.top do
        temp:=temp+stack.items[i]+'  ';

    memo1.Lines.Add(temp);
//將stack資料列印出來-E
end;

procedure TForm1.DelBtnClick(Sender: TObject);
var
   temp:string;
   i:integer;
begin
     if stack.top = 0 then
        begin
             memo1.Lines.Add('堆疊已無任何資料');
             abort;
        end;

//將資料加入stack中-S
    //memo1.Lines.Add('***刪除***' + stack.items[stack.top]);
    stack.items[stack.top]:= '';
    dec(stack.top);

    stack.items[stack.top]:= '';
    dec(stack.top);
//將資料加入stack中-E

//將stack資料列印出來-S
    temp:='';

    for i:=1 to  stack.top do
        temp:=temp+stack.items[i]+'  ';

    memo1.Lines.Add(temp);
//將stack資料列印出來-E
end;
procedure TForm1.Button1Click(Sender: TObject);
var
  ans:integer;
begin
    ans:=Fact(strtoint(inputdataEdt.Text));
    memo1.Lines.Add(inttostr(ans));
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  temp,ans:string;
  i:integer;
begin
  temp:='ABCDEFG';

//  Copy(S; Index, Count: Integer): string;

  //ans:=copy(temp,2,3);
  //memo1.Lines.Add(ans);
  //memo1.Lines.Add( inttostr(length(temp)) );
  for i:=1 to length(temp) do
     begin
          memo1.Lines.Add(copy(temp,i,1));
     end;

  //memo1.Lines.Add(copy(temp,i,1));
end;

procedure TForm1.Button3Click(Sender: TObject);
var
  temp:string;
  i:integer;
  // ans:char;
begin
  temp:='25436';

  for i:=1 to length(temp) do
     begin
          if (copy(temp,i,1) >= '0') and (copy(temp,i,1) <= '9')

          then
             memo1.Lines.Add(copy(temp,i,1));

     end;


end;

end.