Kód: Vybrať všetko

type
TSudoku = class
Pole: array [0..8, 0..8] of integer;
    Opakuje: array [0..8, 0..8] of Boolean;
    Stlpec: array [0..8] of set of 1..9;
    Riadok: array [0..8] of set of 1..9;
    Malystvorec: array [0..2, 0..2] of set of 1..9;
    constructor Create( Memo1:TMemo );
    procedure Vyplnsudoku;
    procedure Backtracking;
    function Moze(r,s, k: integer): Boolean;
end;

var
  Form1: TForm1;

implementation

{$R *.dfm}


procedure TForm1.Button1Click(Sender: TObject);
var
  Sudoku: TSudoku;
begin
 Sudoku := TSudoku.Create( Memo1 );
 Sudoku.Backtracking;
end;

constructor TSudoku.Create( Memo1:TMemo );
var
  sudokutext: TextFile;
  r,s: integer;
begin
 AssignFile(sudokutext, 'sudoku.txt');
 Reset(sudokutext);
 for r := 0 to 8 do
  for s := 0 to 8 do
  begin
   Read(sudokutext, Pole[r,s]);
   Opakuje[r,s] := Pole[r,s] <> 0;
   if Opakuje[r,s] then
   begin
    Stlpec[s] := Stlpec[s] + [Pole[r,s]];
    Riadok[r] := Riadok[r] + [Pole[r,s]];
    Malystvorec[r div 3, s div 3] := Malystvorec[r div 3, s div 3] + [Pole[r,s]];
   end;
  end;
  CloseFile(sudokutext);
  Vyplnsudoku;
end;

procedure TSudoku.Vyplnsudoku;
var
r,s: integer;
begin
 Form1.Memo1.Clear;
 for r := 0 to 8 do begin
 for s := 0 to 8 do
 Form1.Memo1.Text := Form1.Memo1.Text + '   ' + intToStr( Pole[r,s] );
 Form1.Memo1.Text := Form1.Memo1.Text + #13#10;
end;
 Form1.Memo1.Lines.Add( '   ' );
end;


function TSudoku.Moze(r,s, k: integer): Boolean;
begin
  Result := not (k in Riadok[r]) and
            not (k in Stlpec[s]) and
            not (k in Malystvorec[r div 3, s div 3]);
end;

procedure TSudoku.Backtracking;
var
  r,s,k: integer;
begin
 r := 0;
 s := 0;
 while (r < 9) and (Pole[r,s] <> 0) do
 begin
  inc(s);
   if s = 9 then
   begin
    inc(r);
    s := 0;
   end;
 end;
 if r = 9 then
 begin
  Vyplnsudoku;
  end
  else
    for k := 1 to 9 do
    if Moze(r,s, k) then
    begin
     Pole[r,s] := k;
     Stlpec[s] := Stlpec[s] + [k];
     Riadok[r] := Riadok[r] + [k];
     Malystvorec[r div 3, s div 3] := Malystvorec[r div 3, s div 3] + [k];
     Backtracking;
     Pole[r,s] := 0;
     Stlpec[s] := Stlpec[s] - [k];
     Riadok[r] := Riadok[r] - [k];
     Malystvorec[r div 3, s div 3] := Malystvorec[r div 3, s div 3] - [k];
    end;
 end;
end.