Lab 6.3 (Delphi)

unit Unit1;

interface

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

type
    TForm1 = class(TForm)
    StringGridPoints: TStringGrid;
    EditAmount: TEdit;
    ButtonPoints: TButton;
        Memo1: TMemo;
        ButtonFind: TButton;
    MainMenu1: TMainMenu;
    N1: TMenuItem;
    N2: TMenuItem;
    N3: TMenuItem;
    N4: TMenuItem;
    N5: TMenuItem;
    N6: TMenuItem;
    N7: TMenuItem;
    OpenDialog1: TOpenDialog;
    SaveDialog1: TSaveDialog;
        procedure ButtonFindClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure ButtonPointsClick(Sender: TObject);
    procedure EditAmountKeyPress(Sender: TObject; var Key: Char);
    procedure EditAmountChange(Sender: TObject);
    procedure StringGridPointsKeyPress(Sender: TObject; var Key: Char);
    procedure StringGridPointsSetEditText(Sender: TObject; ACol, ARow: Integer;
      const Value: string);
    procedure N3Click(Sender: TObject);
    procedure N7Click(Sender: TObject);
    procedure N4Click(Sender: TObject);
    procedure N5Click(Sender: TObject);
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
    procedure N2Click(Sender: TObject);
    private
        { Private declarations }
    public
        { Public declarations }
    end;

type
    TPoint = record
        X, Y: Double;
    end;

    TLineEquation = class
    private
        FK, FB: Double;
    public
        property K: Double read FK;
        property B: Double read FB;

        function DistanceToLineSquared(X, Y: Double): Double;
        class function FromPoints(X1, Y1, X2, Y2: Double): TLineEquation;
    end;

var
    Form1: TForm1;
    Path: String;
    IsFileOpen: Boolean;

implementation

{$R *.dfm}

function TLineEquation.DistanceToLineSquared(X, Y: Double): Double;
var
    Distance: Double;
begin
    Distance := (FK * X - Y + FB) / Sqrt(FK * FK + 1);
    Result := Distance * Distance;
end;

class function TLineEquation.FromPoints(X1, Y1, X2, Y2: Double): TLineEquation;
var
    Line: TLineEquation;
begin
    Line := TLineEquation.Create;
    If (X2 - X1) <> 0 Then
    Begin
        Line.FK := (Y2 - Y1) / (X2 - X1);
        Line.FB := Y1 - Line.FK * X1;
    End;
    Result := Line;
end;

function FindDividingLine(const Points: TArray<TPoint>): TLineEquation;
var
    Size, I, J, K: Integer;
    BestError, Error: Double;
    BestLine, CurrentLine: TLineEquation;
begin
    Size := Length(Points);
    if Size mod 2 <> 0 then
        raise Exception.Create('Количество точек должно быть четным.');

    BestError := Double.MaxValue;
    BestLine := TLineEquation.Create;

    for I := 0 to Size - 1 do
    begin
        for J := I + 1 to Size - 1 do
        begin
            CurrentLine := TLineEquation.FromPoints(Points[I].X, Points[I].Y,
              Points[J].X, Points[J].Y);

            Error := 0;
            for K := 0 to Size - 1 do
                Error := Error + CurrentLine.DistanceToLineSquared(Points[K].X, Points[K].Y);

            if Error < BestError then
            begin
                BestError := Error;
                BestLine := CurrentLine;
            end;
        end;
    end;
    Result := BestLine;
end;

procedure TForm1.ButtonFindClick(Sender: TObject);
var
    Points: TArray<TPoint>;
    Line: TLineEquation;
    I, Size: Integer;
begin
    Size := StrToInt(EditAmount.Text);
    SetLength(Points, Size);
    For I := 0 to Size - 1 do
    Begin
        Points[I].X := StrToFloat(StringGridPoints.Cells[I + 1, 1]);
        Points[I].Y := StrToFloat(StringGridPoints.Cells[I + 1, 2])
    End;
    Line := FindDividingLine(Points);
    N5.Enabled := True;
    Memo1.Text := 'Уравнение прямой: y = ' + FormatFloat('0.00', Line.K) + 'x + ' + FormatFloat('0.00', Line.B);
end;

procedure TForm1.ButtonPointsClick(Sender: TObject);
var
    Size, I: Integer;
begin

    StringGridPoints.Enabled := True;
    StringGridPoints.Rows[1].Clear;
    StringGridPoints.Rows[2].Clear;
    StringGridPoints.Cells[0,1] := 'X';
    StringGridPoints.Cells[0,2] := 'Y';

    Size := StrToInt(EditAmount.Text);
    StringGridPoints.ColCount := Size + 1;
    For I := 1 to Size do
    Begin
        StringGridPoints.Cells[I, 0] := IntToStr(I);
    End;
    Memo1.Clear;
    ButtonFind.Enabled := False;
    N5.Enabled := False
end;

procedure TForm1.EditAmountChange(Sender: TObject);
var
    num: Integer;
    IsCorrect: Boolean;
begin
    IsCorrect := True;
    try
        num := StrToInt(EditAmount.Text)
    except
        IsCorrect := False;
    end;
    If IsCorrect And (num > 0) And (Num < 100) And (Num mod 2 = 0) Then
    Begin
        ButtonPoints.Enabled := True;
    End
    Else
        ButtonPoints.Enabled := False;
    StringGridPoints.Enabled := False;
    ButtonFind.Enabled := False;
    Memo1.Clear;
    N5.Enabled := False
end;

procedure TForm1.EditAmountKeyPress(Sender: TObject; var Key: Char);
begin
    if not (Key in ['0'..'9', #13, #8]) then
        Key := #0;
    if (Key = #13) And (ButtonPoints.Enabled) then
        ButtonPoints.Click;
end;

procedure TForm1.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
begin
    CanClose := Application.MessageBox('Вы действительно хотите выйти?', 'Выход', MB_ICONQUESTION + MB_YESNO) = ID_YES
end;

procedure TForm1.FormCreate(Sender: TObject);
var
    I: Integer;
begin
    StringGridPoints.Cells[0,0] := '№/№';
    StringGridPoints.Cells[0,1] := 'X';
    StringGridPoints.Cells[0,2] := 'Y';
end;

procedure TForm1.N2Click(Sender: TObject);
const
    Info1 = 'На плоскости заданы 2n точек своими координатами. Найти уравнение'#13#10;
    Info2 = 'какой-либо прямой, делящей данное множество на два подмножества по n точек.'#13#10;
    Info3 = '1. Минимальное количество точек - 2, максимальная - 20.'#13#10;
    Info4 = '2. Количество точек должно быть кратно двум.'#13#10;
    Info5 = '3. Диапазон ввода координат от 0 до 99.'#13#10;
begin
    Application.MessageBox(Info1 + Info2 + Info3 + Info4 + Info5, 'Справка', 0);
end;

procedure TForm1.N3Click(Sender: TObject);
begin
    Application.MessageBox('Сымоник Вадим, гр. 251004', 'Разработчик', 0)
end;

Function GetSize(var FileInput: TextFile): String;
Const
    MIN_NUM = 1;
    MAX_NUM = 100;
Var
    Size, Num: Integer;
    Str: String;
    IsCorrect: Boolean;
Begin
    Size := 0;
    Str := '';
    If Not Eof(FileInput) Then
    Begin
        IsCorrect := True;
        Try
            Read(FileInput, Size);
        Except
            MessageBox(Form1.Handle, PChar('Недопустимый размер массива!'),
              'Ошибка', MB_ICONSTOP);
            IsCorrect := False;
            Size := 0;
        End;
    End
    Else
        MessageBox(Form1.Handle, PChar('Недостаточно данных в файле!'),
          'Ошибка', MB_ICONSTOP);
    If (Size > 0) And (Size <= MAX_NUM) Then
        If Size mod 2 = 0 Then
            Str := IntToStr(Size)
        Else
            Application.MessageBox('Нечетное количество данных', 'Ошибка', 0)
    Else
        Application.MessageBox('Проверьте корректность данных в файле', 'Ошибка', 0);
    GetSize := Str;
End;

Function TakeInformationIntoCell(Var FileInput: TextFile;
  Var IsCorrect: Boolean): String;
Var
    Temp: Integer;
    Str: String;
    StrTemp: String;
Begin
    If Not Eof(FileInput) Then
    Begin
        Try
            Read(FileInput, Temp);
            Str := IntToStr(Temp);
            StrTemp := IntToStr(Abs(Temp));
        Except
            MessageBox(Form1.Handle, PChar('Неверные данные!'), 'Ошибка',
              MB_ICONSTOP);
            IsCorrect := False;
        End;
        If Length(StrTemp) > 2 Then
        Begin
            IsCorrect := False;
            MessageBox(Form1.Handle,
              PChar('Недопустимый диапазон входных данных!'), 'Ошибка',
              MB_ICONSTOP);
            Str := '';
        End;
    End
    Else
    Begin
        IsCorrect := False;
        MessageBox(Form1.Handle, PChar('Недостаточно значений в файле!'),
          'Ошибка', MB_ICONSTOP);
        Str := '';
    End;
    TakeInformationIntoCell := Str;
End;

Procedure InputPointsInMatrix(var FileInput: TextFile);
Var
    I, J: Integer;
    IsCorrect: Boolean;
Begin
    IsCorrect := True;
    With Form1 do
    Begin
        For I := 1 to StringGridPoints.ColCount - 1 do
        Begin
            For J := 1 to StringGridPoints.RowCount - 1 do
            Begin
                StringGridPoints.Cells[I, J] :=
                  TakeInformationIntoCell(FileInput, IsCorrect);
            End;
        End;
        ButtonFind.Enabled := IsCorrect;
    End;
End;

procedure TForm1.N4Click(Sender: TObject);
var
    FileInput: TextFile;
begin
    If OpenDialog1.Execute Then
    Begin
        AssignFile(FileInput, OpenDialog1.FileName);
        Try
            Try
                Reset(FileInput);
                EditAmount.Text := GetSize(FileInput);
                if EditAmount.Text <> '' then
                Begin
                    ButtonPoints.Click;
                    InputPointsInMatrix(FileInput);
                End;
            Finally
                CloseFile(FileInput);
            End;
        Except

        End;
    End;
end;

Function Open(): String;
begin
    with Form1 Do
    begin
        If SaveDialog1.Execute Then
        begin
            Path := SaveDialog1.FileName;
            IsFileOpen := True;
        end
        Else
            IsFileOpen := False;
    end;
    Open := Path;
end;

procedure TForm1.N5Click(Sender: TObject);
var
    F: TextFile;
begin
    Path := Open;
    If IsFileOpen Then
    Begin
        AssignFile(F, Path);
        Rewrite(F);
        Writeln(F, Memo1.Text);
        Application.MessageBox('Данные успешно сохранены в файл',
          'Результат', 0);
        CloseFile(F);
    End;
end;

procedure TForm1.N7Click(Sender: TObject);
begin
    Form1.Close
end;

procedure TForm1.StringGridPointsKeyPress(Sender: TObject; var Key: Char);
begin
    If not (Key in ['0'..'9', #8, #13]) Then
        Key := #0;
    if (Key = #13) And (ButtonFind.Enabled = True) then
        ButtonFind.Click
end;

procedure TForm1.StringGridPointsSetEditText(Sender: TObject; ACol,
  ARow: Integer; const Value: string);

var
    I, J: Integer;
    N: Integer;
    IsCorrect: Boolean;

begin
    IsCorrect := True;
    For I := 1 to StringGridPoints.RowCount - 1 do
    Begin
        for J := 1 to StringGridPoints.ColCount - 1 do
        Begin
            If StringGridPoints.Cells[I, J] <> '' Then
            Try
                N := StrToInt(StringGridPoints.Cells[I, J]);
            Except
                StringGridPoints.Cells[I, J] := '';
                Application.MessageBox('Проверьте корректность введенных данных', 'Ошибка', 0);
            End;

            If Length(StringGridPoints.Cells[I, J]) > 2 Then
            Begin
                StringGridPoints.Cells[I, J] := '';
                Application.MessageBox('Диапазон ввода [0; 99]', 'Ошибка', 0);
            End;
        End;
    End;


    For J := 1 to StringGridPoints.RowCount - 1 do
        for I := 1 to StringGridPoints.ColCount - 1 do
            If Length(StringGridPoints.Cells[I, J]) = 0 Then
                IsCorrect := False;
    ButtonFind.Enabled := IsCorrect;
    Memo1.Clear;
    N5.Enabled := False
end;

end.