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 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 SingleStepSolution SolveSingleStep(SudokuPuzzle sudokuPuzzle)
{
if (sudokuPuzzle.IsSolved())
{
return(null);
}
foreach (var strategy in _strategies)
{
var elimination = _basicElimination.SolveSingleStep(sudokuPuzzle);
if (elimination != null)
{
return(elimination);
}
var solution = strategy.SolveSingleStep(sudokuPuzzle);
if (solution != null)
{
return(solution);
}
}
return(null);
}
