public void TryDrop_LeavesUnchangedOnFailure() { var puzzle = new Puzzle(4); var matrix = new ExactCoverMatrix(puzzle); new RowUniquenessConstraint().Constrain(puzzle, matrix); new ColumnUniquenessConstraint().Constrain(puzzle, matrix); int valueIndex = 0; Assert.True(matrix.GetSquare(new Coordinate(0, 0)).GetPossibleValue(valueIndex).TryDrop()); Assert.True(matrix.GetSquare(new Coordinate(0, 1)).GetPossibleValue(valueIndex).TryDrop()); Assert.True(matrix.GetSquare(new Coordinate(0, 2)).GetPossibleValue(valueIndex).TryDrop()); Square square = matrix.GetSquare(new Coordinate(0, 3)); PossibleValue possibleValue = square.GetPossibleValue(valueIndex); Link linkA = possibleValue.FirstLink; Link linkB = linkA.Right; ConstraintHeader constraintA = linkA.Constraint; ConstraintHeader constraintB = linkB.Constraint; Assert.False(possibleValue.TryDrop()); Assert.Equal(4, square.NumPossibleValues); Assert.Equal(PossibleSquareState.UNKNOWN, possibleValue.State); Assert.Equal(1, constraintA.Count); Assert.Equal(4, constraintB.Count); Assert.Same(linkA, constraintA.FirstLink); Assert.Contains(linkB, constraintB.GetLinks()); }
public void TrySatisfyConstraint_WithNoOtherChoicesOnConnectedPossible_Fails() { var puzzle = new Puzzle(4); var matrix = new ExactCoverMatrix(puzzle); new RowUniquenessConstraint().Constrain(puzzle, matrix); new ColumnUniquenessConstraint().Constrain(puzzle, matrix); Square square = matrix.GetSquare(new Coordinate(0, 0)); Link lastLink = square.AllPossibleValues[0].FirstLink; ConstraintHeader header = lastLink.Constraint; for (int i = 1; i < square.AllPossibleValues.Length; i++) { Assert.True(square.AllPossibleValues[i].TryDrop()); } Link link = lastLink.Down; Assert.False(link.TrySatisfyConstraint()); Assert.False(header.IsSatisfied); Assert.Equal(1, square.NumPossibleValues); Assert.Same(lastLink.PossibleSquare, square.GetStillPossibleValues().Single()); Assert.Equal(PossibleSquareState.UNKNOWN, lastLink.PossibleSquare.State); }
public void Return_WithSatisfiedConstraint_UndropsTheRowAsExpected() { 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, 0)); PossibleValue possibleValue = square.GetPossibleValue(valueIndex); Link linkA = possibleValue.FirstLink; Link linkB = linkA.Right; ConstraintHeader constraintA = linkA.Constraint; ConstraintHeader constraintB = linkB.Constraint; Assert.True(constraintB.TrySatisfyFrom(possibleValue.FirstLink.Right.Up)); possibleValue.Return(); Assert.Equal(4, square.NumPossibleValues); Assert.Equal(PossibleSquareState.UNKNOWN, possibleValue.State); Assert.Equal(4, constraintA.Count); Assert.Equal(4, constraintB.Count); Assert.Contains(linkA, constraintA.GetLinks()); Assert.Contains(linkB, constraintB.GetLinks()); }
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 Constrain_SetsUpSquareLinksForAllPossibleValues() { int size = 4; int[] possibleValues = new int[] { 1, 3, 5, 7 }; var puzzle = new Puzzle(size); var matrix = new ExactCoverMatrix(puzzle); new RowUniquenessConstraint().Constrain(puzzle, matrix); for (int row = 0; row < size; row++) { for (int col = 0; col < size; col++) { foreach (PossibleValue possibleValue in matrix.GetSquare(new Coordinate(row, col)).AllPossibleValues) { Assert.NotNull(possibleValue.FirstLink); } } } }
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()); }
public void TrySatisfyConstraint_Succeeds() { var puzzle = new Puzzle(4); var matrix = new ExactCoverMatrix(puzzle); new RowUniquenessConstraint().Constrain(puzzle, matrix); new ColumnUniquenessConstraint().Constrain(puzzle, matrix); Link link = matrix.GetSquare(new Coordinate(0, 0)).AllPossibleValues[0].FirstLink; ConstraintHeader header = link.Constraint; Assert.True(link.TrySatisfyConstraint()); Assert.True(header.IsSatisfied); Assert.True(link.Constraint.IsSatisfied); // Still connected horizontally. Assert.Same(link, link.Right.Left); Assert.Same(link, link.Left.Right); // Vertically connected links are dropped form possible values. Assert.Equal(PossibleSquareState.DROPPED, link.Up.PossibleSquare.State); Assert.Equal(3, link.Up.PossibleSquare.Square.NumPossibleValues); // Still connected vertically. Assert.Contains(link, link.Constraint.GetLinks()); }
public void TryDrop_DropsOnSuccess() { var puzzle = new Puzzle(4); var matrix = new ExactCoverMatrix(puzzle); new RowUniquenessConstraint().Constrain(puzzle, matrix); new ColumnUniquenessConstraint().Constrain(puzzle, matrix); int valueIndex = 1; Square square = matrix.GetSquare(new Coordinate(1, 0)); PossibleValue possibleValue = square.GetPossibleValue(valueIndex); Link linkA = possibleValue.FirstLink; Link linkB = linkA.Right; ConstraintHeader constraintA = linkA.Constraint; ConstraintHeader constraintB = linkB.Constraint; Assert.True(possibleValue.TryDrop()); Assert.Equal(3, square.NumPossibleValues); Assert.Equal(PossibleSquareState.DROPPED, possibleValue.State); Assert.Equal(3, constraintA.Count); Assert.Equal(3, constraintB.Count); Assert.DoesNotContain(linkA, constraintA.GetLinks()); Assert.DoesNotContain(linkB, constraintB.GetLinks()); }
public void Constrain_ReturnsExpectedConstraints() { int size = 4; int[] possibleValues = new int[] { 1, 3, 5, 7 }; var puzzle = new Puzzle(size); var matrix = new ExactCoverMatrix(puzzle); new RowUniquenessConstraint().Constrain(puzzle, matrix); Assert.Equal(size * possibleValues.Length, matrix.GetUnsatisfiedConstraintHeaders().Count()); ConstraintHeader firstRowConstraint = matrix.GetSquare(new Coordinate(0, 0)).AllPossibleValues[0].FirstLink.Constraint; ConstraintHeader secondRowConstraint = matrix.GetSquare(new Coordinate(1, 0)).AllPossibleValues[0].FirstLink.Constraint; ConstraintHeader thirdRowConstraint = matrix.GetSquare(new Coordinate(2, 0)).AllPossibleValues[0].FirstLink.Constraint; ConstraintHeader fourthRowConstraint = matrix.GetSquare(new Coordinate(3, 0)).AllPossibleValues[0].FirstLink.Constraint; Assert.NotSame(firstRowConstraint, secondRowConstraint); Assert.NotSame(firstRowConstraint, thirdRowConstraint); Assert.NotSame(firstRowConstraint, fourthRowConstraint); Assert.NotSame(secondRowConstraint, thirdRowConstraint); Assert.NotSame(secondRowConstraint, fourthRowConstraint); Assert.NotSame(thirdRowConstraint, fourthRowConstraint); Assert.Same(firstRowConstraint, matrix.GetSquare(new Coordinate(0, 1)).AllPossibleValues[0].FirstLink.Constraint); Assert.Same(firstRowConstraint, matrix.GetSquare(new Coordinate(0, 2)).AllPossibleValues[0].FirstLink.Constraint); Assert.Same(firstRowConstraint, matrix.GetSquare(new Coordinate(0, 3)).AllPossibleValues[0].FirstLink.Constraint); Assert.Same(secondRowConstraint, matrix.GetSquare(new Coordinate(1, 1)).AllPossibleValues[0].FirstLink.Constraint); Assert.Same(secondRowConstraint, matrix.GetSquare(new Coordinate(1, 2)).AllPossibleValues[0].FirstLink.Constraint); Assert.Same(secondRowConstraint, matrix.GetSquare(new Coordinate(1, 3)).AllPossibleValues[0].FirstLink.Constraint); Assert.Same(thirdRowConstraint, matrix.GetSquare(new Coordinate(2, 1)).AllPossibleValues[0].FirstLink.Constraint); Assert.Same(thirdRowConstraint, matrix.GetSquare(new Coordinate(2, 2)).AllPossibleValues[0].FirstLink.Constraint); Assert.Same(thirdRowConstraint, matrix.GetSquare(new Coordinate(2, 3)).AllPossibleValues[0].FirstLink.Constraint); Assert.Same(fourthRowConstraint, matrix.GetSquare(new Coordinate(3, 1)).AllPossibleValues[0].FirstLink.Constraint); Assert.Same(fourthRowConstraint, matrix.GetSquare(new Coordinate(3, 2)).AllPossibleValues[0].FirstLink.Constraint); Assert.Same(fourthRowConstraint, matrix.GetSquare(new Coordinate(3, 3)).AllPossibleValues[0].FirstLink.Constraint); }