public void TrySelect_DropsConstraintConnectedSquareValues()
{
var puzzle = new Puzzle(4);
var matrix = new ExactCoverMatrix(puzzle);
new RowUniquenessConstraint().Constrain(puzzle, matrix);
new ColumnUniquenessConstraint().Constrain(puzzle, matrix);
int valueIndex = 0;
PossibleValue possibleValue = matrix.GetSquare(new Coordinate(0, 1)).GetPossibleValue(valueIndex);
Assert.True(possibleValue.TrySelect());
ConstraintHeader constraintA = possibleValue.FirstLink.Constraint;
ConstraintHeader constraintB = possibleValue.FirstLink.Right.Constraint;
Assert.Equal(4, constraintA.GetLinks().Count());
Assert.Equal(4, constraintB.GetLinks().Count());
foreach (Link link in constraintA.GetLinks())
{
if (link.PossibleSquare == possibleValue)
{
continue;
}
Assert.Equal(PossibleSquareState.DROPPED, link.PossibleSquare.State);
}
foreach (Link link in constraintB.GetLinks())
{
if (link.PossibleSquare == possibleValue)
{
continue;
}
Assert.Equal(PossibleSquareState.DROPPED, link.PossibleSquare.State);
}
}
public void TrySelect_SelectsSquare()
{
var puzzle = new Puzzle(4);
var matrix = new ExactCoverMatrix(puzzle);
new RowUniquenessConstraint().Constrain(puzzle, matrix);
new ColumnUniquenessConstraint().Constrain(puzzle, matrix);
int valueIndex = 0;
Square square = matrix.GetSquare(new Coordinate(0, 1));
PossibleValue possibleValue = square.GetPossibleValue(valueIndex);
Assert.True(possibleValue.TrySelect());
Assert.Equal(PossibleSquareState.SELECTED, possibleValue.State);
}
public void Deselect_WithSelectedValue_SetsStateAndSquareCountCorrectly()
{
var puzzle = new Puzzle(4);
var matrix = new ExactCoverMatrix(puzzle);
new RowUniquenessConstraint().Constrain(puzzle, matrix);
new ColumnUniquenessConstraint().Constrain(puzzle, matrix);
int valueIndex = 0;
Square square = matrix.GetSquare(new Coordinate(0, 1));
PossibleValue possibleValue = square.GetPossibleValue(valueIndex);
Assert.True(possibleValue.TrySelect());
possibleValue.Deselect();
Assert.Equal(PossibleSquareState.UNKNOWN, possibleValue.State);
Assert.Equal(4, square.NumPossibleValues);
}
public void Deselect_WithSelectedValue_ReturnsDroppedRows()
{
var puzzle = new Puzzle(4);
var matrix = new ExactCoverMatrix(puzzle);
new RowUniquenessConstraint().Constrain(puzzle, matrix);
new ColumnUniquenessConstraint().Constrain(puzzle, matrix);
int valueIndex = 0;
Square square = matrix.GetSquare(new Coordinate(0, 1));
PossibleValue possibleValue = square.GetPossibleValue(valueIndex);
Assert.True(possibleValue.TrySelect());
possibleValue.Deselect();
Link linkA = possibleValue.FirstLink;
Link linkB = linkA.Right;
ConstraintHeader constraintA = linkA.Constraint;
ConstraintHeader constraintB = linkB.Constraint;
Assert.False(constraintA.IsSatisfied);
Assert.False(constraintB.IsSatisfied);
Assert.Equal(4, constraintA.Count);
Assert.Equal(4, constraintB.Count);
foreach (Link link in constraintA.GetLinks())
{
if (link != linkA)
{
Assert.Equal(PossibleSquareState.UNKNOWN, link.PossibleSquare.State);
}
}
foreach (Link link in constraintB.GetLinks())
{
if (link != linkB)
{
Assert.Equal(PossibleSquareState.UNKNOWN, link.PossibleSquare.State);
}
}
}
public void TrySelect_SatisfiesConstraints()
{
var puzzle = new Puzzle(4);
var matrix = new ExactCoverMatrix(puzzle);
new RowUniquenessConstraint().Constrain(puzzle, matrix);
new ColumnUniquenessConstraint().Constrain(puzzle, matrix);
int valueIndex = 0;
PossibleValue possibleValue = matrix.GetSquare(new Coordinate(0, 1)).GetPossibleValue(valueIndex);
Assert.True(possibleValue.TrySelect());
ConstraintHeader constraintA = possibleValue.FirstLink.Constraint;
ConstraintHeader constraintB = possibleValue.FirstLink.Right.Constraint;
Assert.True(constraintA.IsSatisfied);
Assert.True(constraintB.IsSatisfied);
Assert.Equal(4, constraintA.Count);
Assert.Equal(4, constraintB.Count);
Assert.DoesNotContain(constraintA, matrix.GetUnsatisfiedConstraintHeaders());
Assert.DoesNotContain(constraintB, matrix.GetUnsatisfiedConstraintHeaders());
}