public void TransformToMagicSquareWithMinimumCostTest()
{
Assert.AreEqual(24, MagicSquares.TransformToMagicSquareWithMinimumCost(new int[, ] {
{ 1, 2, 3 },
{ 4, 5, 6 },
{ 7, 8, 9 }
}));
Assert.AreEqual(7, MagicSquares.TransformToMagicSquareWithMinimumCost(new int[, ] {
{ 5, 3, 4 },
{ 1, 5, 8 },
{ 6, 4, 2 }
}));
Assert.AreEqual(1, MagicSquares.TransformToMagicSquareWithMinimumCost(new int[, ] {
{ 4, 9, 2 },
{ 3, 5, 7 },
{ 8, 1, 5 }
}));
Assert.AreEqual(4, MagicSquares.TransformToMagicSquareWithMinimumCost(new int[, ] {
{ 4, 8, 2 },
{ 4, 5, 7 },
{ 6, 1, 6 }
}));
}
public void ComputeSets_ForNonUniqueValues_Throws()
{
var values = new int[4];
values.AsSpan().Fill(3);
Assert.Throws <ArgumentException>(() => MagicSquares.ComputeSets(values));
}
/// <summary>
/// Constructs a constraint that will enforce that the given <paramref name="squares"/> are
/// magic squares based on the rows, columns, and, optionally, the diagonals.
/// </summary>
/// <param name="possibleValues">
/// The possible values that can be in the magic squares.
/// </param>
/// <param name="squares">
/// The locations of the magic squares.
/// </param>
/// <param name="includeDiagonals">
/// If true, values along the diagonals of the square must also sum to the magic number.
/// </param>
/// <exception cref="ArgumentException">
/// If the any of the given <paramref name="squares"/>' sizes are not compatible with the
/// length of <paramref name="possibleValues"/>.
/// </exception>
public MagicSquaresConstraint(ReadOnlySpan <int> possibleValues, IEnumerable <Box> squares, bool includeDiagonals = true)
{
_size = possibleValues.Length;
_magicSquares = squares.ToArray();
_squareSize = Boxes.IntSquareRoot(_size);
_includeDiagonals = includeDiagonals;
if (_magicSquares.Any(
b =>
b.TopLeft.Row < 0 || b.TopLeft.Column < 0 ||
b.TopLeft.Row + b.Size > _size || b.TopLeft.Column + b.Size > _size ||
b.Size != _squareSize))
{
throw new ArgumentException(
$"Based on the {nameof(possibleValues)}, {nameof(squares)} must fit in a puzzle of size {_size} and have size {_squareSize}.");
}
_allPossibleValues = new BitVector();
for (int i = 0; i < possibleValues.Length; ++i)
{
if (_allPossibleValues.IsBitSet(possibleValues[i]))
{
throw new ArgumentException("Values must be unique.");
}
_allPossibleValues.SetBit(possibleValues[i]);
}
_possibleSets = MagicSquares.ComputeSets(possibleValues, _squareSize, _allPossibleValues);
}
public void ComputeSets_ForNonSquareSizes_Throws(int size)
{
var values = new int[size];
for (int i = 0; i < size; ++i)
{
values[i] = i + 1;
}
Assert.Throws <ArgumentException>(() => MagicSquares.ComputeSets(values));
}
public void ComputeSum_ForStandardValues_Works(int size, int expectedSum)
{
var values = new int[size];
for (int i = 0; i < size; ++i)
{
values[i] = i + 1;
}
Assert.Equal(expectedSum, MagicSquares.ComputeSum(values));
}
