1-Ma’ruza: Dasturlash tillari faniga kirish Reja

unit Unit3;
interface
uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;
type
TForm1 = class(TForm)
Label2: TLabel;
Edit1: TEdit;
Label3: TLabel;
Edit2: TEdit;
Button1: TButton;
Button2: TButton;
Button3: TButton;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
procedure FormActivate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;


implementation
{$R *.DFM}
type
TPStudent=^TStudent;
TStudent = record
f_name:string[20];
l_name: string[20];
next: TPStudent;
end;
var
head: TPStudent;
procedure TForm1.Button1Click(Sender: TObject);
var
node: TPStudent; curr: TPStudent; pre: TPStudent;
begin
new(node); node^.f_name:=Edit1.Text; node^.l_name:=Edit2.Text; curr:=head; pre:=NIL;
while (curr<>NIL) and (node.f_name > curr^.f_name) do
begin pre:= curr; curr:=curr^.next; end;
if pre = NIL then
begin node^.next:=head; head:=node; end
else
begin node^.next:=pre^.next; pre^.next:=node; end;
Edit1.text:='';
Edit2.text:='';
Edit1.SetFocus;
end;
procedure TForm1.Button2Click(Sender: TObject);
var curr: TPStudent; n:integer; st:string;
begin n := 0; st := ''; curr := head;
while curr <> NIL do
begin n := n + 1; st := st + curr^.f_name + ' ' + curr^.l_name+#13; curr := curr^.next;