public void Solve_GivenANonEmptyMatrix_CreatesARoot()
{
// Arrange
var dlxSolver = new DlxSolver();
// Act
var actual = dlxSolver.Solve(_matrix);
// Assert
Assert.That(dlxSolver.Root, Is.Not.Null);
}
public void Solve_GivenANonEmptyMatrix_Creates4ColumnsLinkedViaPrevious()
{
// Arrange
var dlxSolver = new DlxSolver();
// Act
var actual = dlxSolver.Solve(_matrix);
// Assert
var numColumns = 0;
for (var columnHeader = dlxSolver.Root.PreviousColumnHeader; columnHeader != dlxSolver.Root; columnHeader = columnHeader.PreviousColumnHeader)
numColumns++;
Assert.That(numColumns, Is.EqualTo(4));
}
public void Solve_GivenANonEmptyMatrix_CreatesColumnsOfTheCorrectSize()
{
// Arrange
var dlxSolver = new DlxSolver();
// Act
var actual = dlxSolver.Solve(_matrix);
// Assert
var columnHeader1 = dlxSolver.Root.NextColumnHeader;
var columnHeader2 = columnHeader1.NextColumnHeader;
var columnHeader3 = columnHeader2.NextColumnHeader;
var columnHeader4 = columnHeader3.NextColumnHeader;
Assert.That(columnHeader1.Size, Is.EqualTo(2));
Assert.That(columnHeader2.Size, Is.EqualTo(2));
Assert.That(columnHeader3.Size, Is.EqualTo(3));
Assert.That(columnHeader4.Size, Is.EqualTo(2));
Assert.That(columnHeader4.NextColumnHeader, Is.EqualTo(dlxSolver.Root));
Assert.That(columnHeader1.PreviousColumnHeader, Is.EqualTo(dlxSolver.Root));
Assert.That(dlxSolver.Root.PreviousColumnHeader, Is.EqualTo(columnHeader4));
}
public void Solve_GivenANonEmptyMatrix_CreatesFirstColumnWithCorrectLinks()
{
// Arrange
var dlxSolver = new DlxSolver();
// Act
var actual = dlxSolver.Solve(_matrix);
// Assert
var firstColumnHeader = dlxSolver.Root.NextColumnHeader;
var firstNodeInColumn = firstColumnHeader.Down;
var secondNodeInColumn = firstNodeInColumn.Down;
Assert.That(firstNodeInColumn.Up, Is.EqualTo(firstColumnHeader));
Assert.That(secondNodeInColumn.Up, Is.EqualTo(firstNodeInColumn));
Assert.That(secondNodeInColumn.Down, Is.EqualTo(firstColumnHeader));
Assert.That(firstNodeInColumn.Left, Is.EqualTo(firstNodeInColumn));
Assert.That(firstNodeInColumn.Right, Is.EqualTo(firstNodeInColumn));
Assert.That(firstNodeInColumn.ColumnHeader, Is.EqualTo(firstColumnHeader));
Assert.That(secondNodeInColumn.ColumnHeader, Is.EqualTo(firstColumnHeader));
}
public void Solve_GivenTheMatrixFromTheJanMagneTjensvoldPaper_ReturnsThe3ExpectedSolutions()
{
// Arrange
var dlxSolver = new DlxSolver();
// Act
var actual = dlxSolver.Solve(_matrix);
// Assert
var solutions = actual.ToList();
Assert.That(solutions, Has.Count.EqualTo(3));
Assert.That(solutions, Has.Member(new[] { 0, 3, 4 }));
Assert.That(solutions, Has.Member(new[] { 1, 2 }));
Assert.That(solutions, Has.Member(new[] { 2, 4, 5 }));
}
public void Solve_GivenTheMatrixFromJanMagneTjensvoldPaper_ReturnsSomeSolutions()
{
// Arrange
var dlxSolver = new DlxSolver();
// Act
var actual = dlxSolver.Solve(_matrix);
// Assert
Assert.That(actual, Has.Count.GreaterThan(0));
}
public void Solve_GivenEmptyMatrix_Returns1EmptySolution()
{
// Arrange
var dlxSolver = new DlxSolver();
var emptyMatrix = new bool[0,0];
// Act
var actual = dlxSolver.Solve(emptyMatrix);
// Assert
Assert.That(actual, Has.Count.EqualTo(1));
Assert.That(actual.First(), Has.Count.EqualTo(0));
}
public IEnumerable<IEnumerable<int>> FindAllSolutions()
{
BuildMatrixAndDictionary();
var dlxSolver = new DlxSolver();
return dlxSolver.Solve(_matrix);
}