Lazarus (Pascal): Отсортировать таблицу StringGrid1 учеников, оставить только тех, у кого средний балл больше 4.5

 unit Unit1; 
 
{$mode objfpc}{$H+} 
 
interface 
 
uses 
  Classes, SysUtils, Forms, Controls, Graphics, Dialogs, Grids, StdCtrls; 
 
type 
 
  { TForm1 } 
 
  TForm1 = class(TForm) 
    Button1: TButton; 
    Button2: TButton; 
    StringGrid1: TStringGrid; 
    procedure Button1Click(Sender: TObject); 
    procedure Button2Click(Sender: TObject); 
    procedure FormCreate(Sender: TObject); 
  private 
  public 
  end; 
 
var 
  Form1: TForm1; 
 
const 
  N_MAX = 3; 
  INDEX_COL = 0; 
  TITLE_ROW = 0; 
  SEARCH_COLOR = clYellow; 
 
type 
  t_student = record 
    name : string[25]; 
    inf : 0..5; 
    phys : 0..5; 
    math : 0..5; 
    sr_ball : real; 
  end; 
 
  var 
  stud : array[1..N_MAX] of t_student; 
 
implementation 
 
{$R *.lfm}  
{ TForm1 } 
 
procedure TForm1.Button1Click(Sender: TObject); 
var 
  stud1, stud2, stud3 : t_student; 
  i: Byte; 
  
begin 
   stud1.name := 'Бабурин'; 
   stud1.inf := 4; 
   stud1.phys := 4; 
   stud1.math := 5; 
   stud1.sr_ball := (stud1.inf + stud1.math + stud1.phys)/3; 
 
   with stud2 do begin 
     name := 'Васильев'; 
     inf := 5; 
     phys := 5; 
     math := 5; 
     sr_ball := (inf + math + phys)/3; 
   end; 
 
   with stud3 do begin 
     name := 'Дьяконова'; 
     inf := 2; 
     phys := 3; 
     math := 3; 
     sr_ball := (inf + math + phys)/3; 
   end; 
   i := 1; 
   StringGrid1.Cells[1,i] := stud1.name; 
   StringGrid1.Cells[2,i] := IntToStr(stud1.inf); 
   StringGrid1.Cells[3,i] := IntToStr(stud1.phys); 
   StringGrid1.Cells[4,i] := IntToStr(stud1.math); 
   StringGrid1.Cells[5,i] := FloatToStrF(stud1.sr_ball,ffFixed,1,2); 
   i := 2; 
   with stud2 do begin 
   StringGrid1.Cells[1,i] := name; 
   StringGrid1.Cells[2,i] := IntToStr(inf); 
   StringGrid1.Cells[3,i] := IntToStr(phys); 
   StringGrid1.Cells[4,i] := IntToStr(math); 
   StringGrid1.Cells[5,i] := FloatToStrF(sr_ball,ffFixed,1,2); 
   end; 
   i := 3; 
   with stud3 do begin 
   StringGrid1.Cells[1,i] := name; 
   StringGrid1.Cells[2,i] := IntToStr(inf); 
   StringGrid1.Cells[3,i] := IntToStr(phys); 
   StringGrid1.Cells[4,i] := IntToStr(math); 
   StringGrid1.Cells[5,i] := FloatToStrF(sr_ball,ffFixed,1,2); 
   end;  
end; 
 
procedure TForm1.Button2Click(Sender: TObject); 
var i: Byte; 
begin 
  for i := 1 to N_MAX do 
   begin 
        if stud[i].sr_ball >= 4.5 then 
            begin 
               StringGrid1.RowHeights[i] := 30; 
            end 
        else 
            StringGrid1.RowHeights[i] := 0; 
   end; 
end; 
 
procedure TForm1.FormCreate(Sender: TObject); 
var 
  i: 0..N_MAX; 
begin 
   for i := 1 to N_MAX do begin 
     StringGrid1.Cells[INDEX_COL, i] := IntToStr(i); 
   end; 
 
   StringGrid1.Cells[0, TITLE_ROW] := 'N'; 
   StringGrid1.Cells[1, TITLE_ROW] := 'Фамилия'; 
   StringGrid1.Cells[2, TITLE_ROW] := 'Информатика'; 
   StringGrid1.Cells[3, TITLE_ROW] := 'Физика'; 
   StringGrid1.Cells[4, TITLE_ROW] := 'Математика'; 
   StringGrid1.Cells[5, TITLE_ROW] := 'Ср. балл'; 
   StringGrid1.ColWidths[1] := 110; 
   StringGrid1.ColWidths[2] := 110; 
   StringGrid1.ColWidths[3] := 60; 
   StringGrid1.ColWidths[4] := 110; 
   StringGrid1.ColWidths[5] := 110; 
  
end; 
end.