---

unit Un123213213213it1;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Edit2: TEdit;
    Edit3: TEdit;
    Edit4: TEdit;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    ListBox1: TListBox;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  Close;

end;

procedure TForm1.Button2Click(Sender: TObject);
begin
   var
  A, B, C: Double;
  x, y: Integer;
  CodeA, CodeB, CodeC: Integer;
  LeftPart: Double;
  Found: Boolean;
begin
  ListBox1.Clear;
  Found := False;

  Val(Edit2.Text, A, CodeA);
  Val(Edit3.Text, B, CodeB);
  Val(Edit4.Text, C, CodeC);

  if (CodeA <> 0) or (CodeB <> 0) or (CodeC <> 0) then
  begin
    ShowMessage('Oshibka A B ili C');
    Exit;
  end;

  if (A = 0) and (B = 0) then
  begin
    ShowMessage('Parametri A i B ne mogut bit 0');
    Exit;
  end;

  for x := -20 to 20 do
    for y := -20 to 20 do
    begin
      LeftPart := A * x * x + B * y * y;
      if Abs(LeftPart - C) < 1E-9 then
      begin
        ListBox1.Items.Add(
          Format('x = %d, y = %d  (%.1f*%d^2 + %.1f*%d^2 = %.1f)',
            [x, y, A, x, B, y, C]));
        Found := True;
      end;
    end;

  if not Found then
    ListBox1.Items.Add('Resheniy v diapazone -20..20 ne najdeno');
end;
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
 ListBox1.Sorted := True;
end;

end.