public SudokuPuzzle GenerateSudoku(SudokuDifficuty difficulty, int length = 9)
{
// get randomly filled out sudoku
SudokuPuzzle solution = SolveSudoku(new SudokuPuzzle());
SudokuPuzzle sudoku = (SudokuPuzzle)solution.Clone();
// check how many fields need to be removed (depending on desired difficulty)
int fieldsToRemove = ((length * length) - (int)difficulty);
while (fieldsToRemove > 0)
{
int freeFieldsCount = sudoku.GetFreeFields().Count;
foreach (var field in sudoku.GetSetFields().Shuffle())
{
if (fieldsToRemove > 0 && isFieldDetermined(sudoku, solution, field.RowIndex, field.ColumnIndex))
{
field.SetValue(0);
fieldsToRemove--;
}
}
// check if progress was made (if not => try with another sudoku puzzle)
if ((freeFieldsCount - sudoku.GetFreeFields().Count) == 0)
{
sudoku = GenerateSudoku(difficulty, length);
break;
}
}
// check if the generated sudoku is unique. if not create a new one.
return((HasSudokuUniqueSolution(sudoku)) ? sudoku : GenerateSudoku(difficulty, length));
}
public SudokuPuzzle GenerateSudoku(SudokuDifficuty difficulty, int length = 9)
{
// get filled out random sudoku
var solver = new SudokuSolver();
var sudoku = solver.SolveSudoku(new SudokuPuzzle());
// reset several values (depending on desired difficulty)
for (int i = 0; i < (length * length) - (int)difficulty; i++)
{
var field = sudoku.GetSetFields().ChooseRandom();
field.SetValue(0);
}
// check if sudoku has a unique solution (if not, generate a new one and repeat procedure)
sudoku = (!solver.HasSudokuUniqueSolution(sudoku)) ? GenerateSudoku(difficulty) : sudoku;
return(sudoku);
}
public SudokuPuzzle GenerateSudoku(SudokuDifficuty difficulty, int length = 9)
{
// get randomly filled out sudoku
SudokuPuzzle source = SolveSudoku(new SudokuPuzzle());
SudokuPuzzle result;
int i;
int fieldsToRemove = ((length * length) - (int)difficulty);
//DateTime genStart = DateTime.Now;
//Console.WriteLine($"====================================================");
do
{
result = (SudokuPuzzle)source.Clone();
result.GetFields1D().ChooseRandom().SetValue(0);
for (i = 0; i < fieldsToRemove; i++)
{
//DateTime start = DateTime.Now;
if (!removeField(result, source))
{
break;
}
//DateTime end = DateTime.Now;
//Console.WriteLine($"iteration { i } took { (end - start).TotalMilliseconds } ms");
}
//if (i < fieldsToRemove) { Console.WriteLine($"generator failed"); }
//else { Console.WriteLine($"generator successful (total time elapsed: { (DateTime.Now - genStart).TotalMilliseconds } ms)"); }
}while (i < fieldsToRemove);
//Console.WriteLine($"====================================================");
return(result);
}