unit LAB_4_1_Form;

interface

uses
   Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
   System.Classes, Vcl.Graphics,
   Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.Grids, Vcl.StdCtrls, Vcl.Menus,
   AboutDev;

const
   MAX_GRID_WIDTH_AMOUNT = 8;
   MAX_GRID_HEIGHT_AMOUNT = 8;
   MAX_EDT_LEN = 9;
   BYTE_MAX_VAL = 255;

type
   T2DArray = array of array of Integer;
   TSet = set of Byte;

   TForm1 = class(TForm)
      sgA: TStringGrid;
      btnCreate: TButton;
      Button1: TButton;
      btnClear: TButton;
      lblN: TLabel;
      edtN: TEdit;
      btnCalc: TButton;
      lblAns: TLabel;
      edtAns: TEdit;
      MainMenu1: TMainMenu;
      N1: TMenuItem;
      N2: TMenuItem;
      N3: TMenuItem;
      N4: TMenuItem;
      N5: TMenuItem;
      N6: TMenuItem;
      odDialog: TOpenDialog;
      sdDialog: TSaveDialog;
      procedure btnCalcClick(Sender: TObject);
      procedure btnCreateClick(Sender: TObject);
      procedure Button1Click(Sender: TObject);
      procedure FormCreate(Sender: TObject);
      procedure btnClearClick(Sender: TObject);
      procedure sgAKeyPress(Sender: TObject; var Key: Char);
      procedure edtNKeyPress(Sender: TObject; var Key: Char);
      procedure N6Click(Sender: TObject);
      procedure N5Click(Sender: TObject);
      procedure N2Click(Sender: TObject);
      procedure N3Click(Sender: TObject);
   private
      { Private declarations }
   public
      { Public declarations }
   end;

var
   Form1: TForm1;
   Matr: T2DArray;

implementation

{$R *.dfm}

function Det(M: T2DArray; P: Integer; Exc: TSet): Integer;
var
   I: Byte;
   Ans, Mul, BDet, IP: Integer;
begin
   Ans := 0;
   IP := 0;
   for I := 0 to Length(M[0]) - 1 do
      if not(I in Exc) then
      begin
         if P = Length(M[0]) - 1 then
         begin
            BDet := M[P, I];
            Ans := BDet;
         end
         else
         begin
            if (IP mod 2 = 0) then
               Mul := 1
            else
               Mul := -1;
            Include(Exc, I);
            BDet := Det(M, P + 1, Exc);
            Exclude(Exc, I);
            Ans := Ans + Mul * M[P, I] * BDet;
         end;
         Inc(IP);
      end;
   Result := Ans;
end;

procedure CorrectStringGridView(var Grid: TStringGrid);
var
   Mul: Integer;
begin

   if Grid.Name = 'sgA' then
      Mul := MAX_GRID_WIDTH_AMOUNT
   else
      Mul := 1;
   if Grid.ColCount > MAX_GRID_WIDTH_AMOUNT then
      Grid.Height := Grid.DefaultRowHeight * Mul +
        GetSystemMetrics(SM_CXHSCROLL) + 3 + Mul
   else
      Grid.Height := Grid.DefaultRowHeight * Mul + 3 + Mul;
   if Grid.RowCount > MAX_GRID_HEIGHT_AMOUNT then
      Grid.Width := Grid.DefaultColWidth * Mul +
        GetSystemMetrics(SM_CXHSCROLL) + 3 + Mul
   else
      Grid.Width := Grid.DefaultColWidth * MAX_GRID_WIDTH_AMOUNT + 3 +
        MAX_GRID_WIDTH_AMOUNT;

end;

procedure TForm1.btnCreateClick(Sender: TObject);
var
   N: Integer;
begin
   with sgA do
   begin
      try
         N := StrToInt(edtN.Text);
      except
         MessageBox(0, PChar('Поля не дожны быть пустыми!'), 'Внимание',
           MB_ICONWARNING);
         Exit;
      end;
      if N > 11 then
      begin
         MessageBox(0, PChar('Порядок матрицы не должн превышать 11'),
           'Внимание', MB_ICONWARNING);
         Exit;
      end;
      ColCount := N;
      RowCount := N;
   end;
   CorrectStringGridView(sgA);
end;

procedure EnableOutElements;
begin
   with Form1 do
   begin
      lblAns.Visible := True;
      edtAns.Visible := True;
   end;
end;

procedure DisableOutElements;
begin
   with Form1 do
   begin
      lblAns.Visible := False;
      edtAns.Visible := False;
   end;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
   I, J: Integer;
begin
   Randomize;
   with sgA do
   begin
      SetLength(Matr, ColCount, ColCount);
      for I := 0 to ColCount - 1 do
         for J := 0 to ColCount - 1 do
            Cells[I, J] := IntToStr(1 + Random(ColCount * ColCount));
   end;
end;

procedure TForm1.btnClearClick(Sender: TObject);
var
   I, J: Integer;
begin
   DisableOutElements;
   with sgA do
   begin
      for I := 0 to ColCount - 1 do
         for J := 0 to ColCount - 1 do
            Cells[J, I] := '';
      ColCount := 0;
      RowCount := 0;
   end;
   edtN.Text := '';
end;

procedure TForm1.btnCalcClick(Sender: TObject);
var
   I, J: Integer;
begin
   with sgA do
   begin
      SetLength(Matr, ColCount, ColCount);
      for I := 0 to ColCount - 1 do
         for J := 0 to ColCount - 1 do
            try
               Matr[I, J] := StrToInt(Cells[J, I]);
            except
               MessageBox(0, PChar('Ячейки не должны быть пустыми'),
                 PChar('Внимание!'), MB_ICONERROR);
               Exit;
            end;
   end;
   edtAns.Text := IntToStr(Det(Matr, 0, []));
   EnableOutElements;
end;

procedure CorrectExtendedInput(var EditText: TEdit; var Key: Char);
begin
   if not(Key in [#8, #13, '0' .. '9', ',']) then
   begin
      Key := #0;
   end
   else if (Key = ',') and (Pos(Key, EditText.Text) > 0) then
   begin
      Key := #0;
   end
end;

procedure TForm1.edtNKeyPress(Sender: TObject; var Key: Char);
begin
   DisableOutElements;
   CorrectExtendedInput(edtN, Key);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
   with sgA do
   begin
      ColWidths[0] := DefaultColWidth;
      Width := DefaultColWidth * MAX_GRID_WIDTH_AMOUNT + 3 +
        MAX_GRID_WIDTH_AMOUNT;
      Height := DefaultRowHeight * MAX_GRID_WIDTH_AMOUNT + 3 +
        MAX_GRID_WIDTH_AMOUNT;
   end;
end;

procedure TForm1.N2Click(Sender: TObject);
var
   InputFile: TextFile;
   FileName: String;
   StopReadN: Boolean;
   I, J, ErrorPos, N, Buf: Integer;
   RawInput: String;
begin
   if odDialog.Execute then
   begin
      FileName := odDialog.FileName;
      AssignFile(InputFile, FileName);
      if FileExists(FileName) then
      begin
         Reset(InputFile);
         StopReadN := False;
         Readln(InputFile, RawInput);
         edtN.Text := RawInput;
         Val(RawInput, N, ErrorPos);
         if N > 0 then
         begin
            StopReadN := True;
            edtN.Text := IntToStr(N);
         end
         else
            ShowMessage('Порядок матрицы должен быть больше нуля...');
         if StopReadN then
         begin
            btnCreate.Click;
            CorrectStringGridView(sgA);
            for I := 0 to N - 1 do
            begin
               for J := 0 to N - 1 do
               begin
                  if SeekEof(InputFile) then
                  begin
                     MessageBox(0, PChar('Недостаточно данных.'), 'Warning',
                       MB_OK + MB_ICONERROR);
                     btnClear.Click;
                     Break;
                  end
                  else
                  begin
                     try
                        Read(InputFile, Buf);
                        sgA.Cells[J, I] := IntToStr(Buf);
                     except
                        MessageBox(0,
                          PChar('Файл содержит некорректные данные...'),
                          'Warning', MB_OK + MB_ICONERROR);
                        btnClear.Click;
                        DisableOutElements;
                        Exit;
                     end;
                  end;
               end;
            end;
         end;
         CloseFile(InputFile);
      end;
   end;
end;

procedure TForm1.N3Click(Sender: TObject);
var
   OutputFile: TextFile;
   FileName: String;
   buttonSelected: Integer;
   I, J: Integer;
begin
   if sdDialog.Execute then
   begin
      FileName := sdDialog.FileName;
      AssignFile(OutputFile, FileName);
      if FileExists(FileName) then
      begin
         buttonSelected := MessageDlg('Такой фай уже существует, перезаписать?',
           mtCustom, [mbYes, mbNo], 0);
         if buttonSelected = mrNo then
            Append(OutputFile)
         else
         begin
            Rewrite(OutputFile);
         end;
      end
      else
         Rewrite(OutputFile);
      Writeln(OutputFile, IntToStr(sgA.ColCount));
      for I := 0 to sgA.ColCount - 1 do
      begin
         for J := 0 to sgA.ColCount - 1 do
            Write(OutputFile, sgA.Cells[J, I] + ' ');
         Writeln(OutputFile);
      end;
      CloseFile(OutputFile);
   end;
end;

procedure TForm1.N5Click(Sender: TObject);
begin
   MessageBox(0, 'Задание:' + #13#13 +
     'Вычислить определитель заданной матрицы, пользуясь формулой разложения по первой строке.',
     'О программе', MB_OK);
end;

procedure TForm1.N6Click(Sender: TObject);
begin
   AboutMe.Show;
end;

procedure TForm1.sgAKeyPress(Sender: TObject; var Key: Char);
begin
   with sgA do
   begin
      if not(Key in [#9, #8, '0' .. '9', '-']) then
      begin
         Key := #0;
      end
      else if (Key = '-') and (Pos(Key, Cells[Col, Row]) > 0) then
      begin
         Key := #0;
      end
      else if (Key = '-') and (Cells[Col, Row] <> '') then
      begin
         Key := #0;
      end
      else if (Length(Cells[Col, Row]) + 1 > MAX_EDT_LEN) and not(Key = #8) then
         Key := #0
   end;
   DisableOutElements;
end;

end.