public void ApplyValidSingleStepSolutionTest()
{
var sudoku = (int[, ])_sudoku.Clone();
sudoku[4, 7] = 0;
var sudokuPuzzle = new SudokuPuzzle(sudoku);
var strategyWhichFindsNothing = new NakedTriple();
var strategyWhichReducesCandidates = new BasicElimination();
var strategyWhichFindsResult = new HiddenSingle();
sudokuPuzzle.ApplySingleStepSolution(strategyWhichFindsNothing.SolveSingleStep(sudokuPuzzle));
Assert.That(sudokuPuzzle.Steps, Is.Empty);
Assert.That(sudokuPuzzle.NumberOfSteps, Is.Zero);
sudokuPuzzle.ApplySingleStepSolution(strategyWhichReducesCandidates.SolveSingleStep(sudokuPuzzle));
Assert.That(sudokuPuzzle.Steps.Count, Is.EqualTo(1));
Assert.That(sudokuPuzzle.NumberOfSteps, Is.EqualTo(1));
Assert.That(sudokuPuzzle.Steps.Last().Strategy, Is.EqualTo(strategyWhichReducesCandidates.StrategyName));
Assert.That(sudokuPuzzle.Steps.Last().SolutionDescription, Is.Not.Empty);
sudokuPuzzle.ApplySingleStepSolution(strategyWhichFindsResult.SolveSingleStep(sudokuPuzzle));
Assert.That(sudokuPuzzle.Steps.Count, Is.EqualTo(2));
Assert.That(sudokuPuzzle.NumberOfSteps, Is.EqualTo(2));
Assert.That(sudokuPuzzle.Steps.Last().Strategy, Is.EqualTo(strategyWhichFindsResult.StrategyName));
Assert.That(sudokuPuzzle.Cells[4, 7].Value, Is.EqualTo(5));
Assert.That(sudokuPuzzle.Steps.Last().SolutionDescription, Is.Not.Empty);
}
public void ApplyInvalidSingleStepSolutionTest()
{
var sudokuPuzzle = new SudokuPuzzle(_sudoku);
Assert.That(() => sudokuPuzzle.ApplySingleStepSolution(null), Throws.Nothing);
Assert.That(sudokuPuzzle.Steps, Is.Empty);
Assert.That(sudokuPuzzle.NumberOfSteps, Is.Zero);
var solutionWithNoEliminations = new SingleStepSolution(new SingleStepSolution.Candidate[0], "test");
Assert.That(() => sudokuPuzzle.ApplySingleStepSolution(solutionWithNoEliminations), Throws.Nothing);
Assert.That(sudokuPuzzle.Steps, Is.Empty);
Assert.That(sudokuPuzzle.NumberOfSteps, Is.Zero);
}
private SingleStepSolution ExecuteStep(SudokuPuzzle sudokuPuzzle, ISudokuSolverStrategy sudokuSolverStrategy)
{
var elimination = _basicElimination.SolveSingleStep(sudokuPuzzle);
if (elimination != null)
{
sudokuPuzzle.ApplySingleStepSolution(elimination);
}
return(sudokuSolverStrategy.SolveSingleStep(sudokuPuzzle));
}
public SudokuPuzzle SolveUsingStrategy(SudokuPuzzle sudokuPuzzle, ISudokuSolverStrategy sudokuSolverStrategy)
{
var step = ExecuteStep(sudokuPuzzle, sudokuSolverStrategy);
while (step != null)
{
sudokuPuzzle.ApplySingleStepSolution(step);
step = ExecuteStep(sudokuPuzzle, sudokuSolverStrategy);
}
return(sudokuPuzzle);
}
private void OnKeyDown(object sender, KeyEventArgs e)
{
// if arrow key was pressed, do navigation
if (ProcessArrowKey(e.Key))
{
return;
}
// if there is no active cell or active cell already has value
if (_activeCell == null || _activeCell.Cell.HasValue)
{
return;
}
// if a non-valid number was entered
var enteredValue = GetKeyValue(e.Key);
if (enteredValue <= 0)
{
return;
}
// if value is not correct or solver cannot solve the puzzle (so we do not know if the value is correct), we do not allow it
var solvedValue = SolvedSudokuPuzzle.Cells[_activeCell.Cell.RowIndex, _activeCell.Cell.ColumnIndex].Value;
var mainViewModel = (MainViewModel)DataContext;
if (solvedValue == 0)
{
mainViewModel.AppendMessage("Cannot enter value because solver cannot solve the puzzle");
return;
}
if (enteredValue != solvedValue)
{
mainViewModel.AppendMessage($"Row {_activeCell.Cell.RowIndex + 1} Column {_activeCell.Cell.ColumnIndex + 1} Value {enteredValue} [Wrong value entered by user]");
return;
}
var solution = new SingleStepSolution(_activeCell.Cell.RowIndex, _activeCell.Cell.ColumnIndex, enteredValue, "Entered by user");
SudokuPuzzle.ApplySingleStepSolution(solution);
_activeCell.NotifyCellValueChanged();
SetSelection(_activeCell);
mainViewModel.AppendMessage(solution.SolutionDescription);
mainViewModel.UpdateStatusMessage();
}
public void UndoSingleStepSolutionsWhichReturnsEliminations_UndoesEliminations_Test()
{
var sudoku = (int[, ])_sudoku.Clone();
sudoku[4, 7] = 0;
var sudokuPuzzle = new SudokuPuzzle(sudoku);
var strategyWhichReducesCandidates = new BasicElimination();
sudokuPuzzle.ApplySingleStepSolution(strategyWhichReducesCandidates.SolveSingleStep(sudokuPuzzle));
Assert.That(sudokuPuzzle.Cells[4, 7].CanBe.Single(), Is.EqualTo(5));
var step = sudokuPuzzle.UndoLastSingleStepSolution();
Assert.That(step.Eliminations, Is.Not.Empty);
Assert.That(step.Result, Is.Null);
Assert.That(step.Strategy, Is.EqualTo(strategyWhichReducesCandidates.StrategyName));
Assert.That(step.SolutionDescription, Is.Not.Empty);
CollectionAssert.AreEqual(sudokuPuzzle.Cells[4, 7].CanBe, new[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 });
}
/// <inheritdoc />
public SudokuPuzzle Solve(int[,] sudoku)
{
var sudokuPuzzle = new SudokuPuzzle(sudoku);
while (!sudokuPuzzle.IsSolved())
{
var solution = SolveSingleStep(sudokuPuzzle);
if (solution == null)
{
// Sudoku cannot be solved :(
sudokuPuzzle = _sudokuPuzzleAfterFailedSolveSingleStep;
break;
}
else
{
sudokuPuzzle.ApplySingleStepSolution(solution);
_sudokuPuzzleAfterFailedSolveSingleStep = sudokuPuzzle;
}
}
return(sudokuPuzzle);
}
public void UndoSingleStepSolutionsWhichReturnsResult_UndoesResult_Test()
{
var sudoku = (int[, ])_sudoku.Clone();
sudoku[4, 7] = 0;
var sudokuPuzzle = new SudokuPuzzle(sudoku);
var strategyWhichFindsResult = new HiddenSingle();
sudokuPuzzle.ApplySingleStepSolution(strategyWhichFindsResult.SolveSingleStep(sudokuPuzzle));
Assert.That(sudokuPuzzle.Cells[4, 7].Value, Is.EqualTo(5));
var step = sudokuPuzzle.UndoLastSingleStepSolution();
Assert.That(step.Eliminations, Is.Null);
Assert.That(step.Result, Is.Not.Null);
Assert.That(step.Result.IndexOfRow, Is.EqualTo(4));
Assert.That(step.Result.IndexOfColumn, Is.EqualTo(7));
Assert.That(step.Strategy, Is.EqualTo(strategyWhichFindsResult.StrategyName));
Assert.That(step.SolutionDescription, Is.Not.Empty);
Assert.That(sudokuPuzzle.Cells[4, 7].Value, Is.EqualTo(0));
}