/// <summary>
/// Computes each unique set of values of length SquareRoot(values.Length) that can be
/// formed from the given values.
/// </summary>
/// <param name="values">
/// All the possible values for the magic square. Each value must be unique.
/// </param>
public static HashSet <BitVector> ComputeSets(ReadOnlySpan <int> values)
{
int boxSize = Boxes.IntSquareRoot(values.Length);
BitVector allPossibleValues = new BitVector();
for (int i = 0; i < values.Length; ++i)
{
if (allPossibleValues.IsBitSet(values[i]))
{
throw new ArgumentException("Values must be unique.");
}
allPossibleValues.SetBit(values[i]);
}
return(ComputeSets(values, boxSize, allPossibleValues));
}
internal static string ToString(IReadOnlyPuzzle puzzle)
{
int size = puzzle.Size;
bool showBoxes = Boxes.TryIntSquareRoot(size, out int boxSize);
if (showBoxes)
{
return(_ToStringWithBoxes(puzzle, boxSize));
}
int maxDigit = puzzle.AllPossibleValuesSpan.FindMax();
var shape = new PuzzleShape {
Size = size,
SquareWidth = maxDigit.ToString(NumberFormatInfo.InvariantInfo).Length
};
var normalChars = _GetCharsForNormalRow();
var strBuild = new StringBuilder();
for (int row = 0; row < size; row++)
{
_AppendDividerRow(shape, _GetCharsForDivider(row, shape), strBuild);
strBuild.Append(normalChars.RowStart);
for (int col = 0; col < size; col++)
{
_AppendSquareContents(puzzle[row, col], shape, strBuild);
if (col == size - 1)
{
strBuild.Append(normalChars.RowEnd);
}
else
{
strBuild.Append(normalChars.BetweenColumns);
}
}
strBuild.Append('\n');
}
_AppendDividerRow(shape, _GetCharsForDivider(size, shape), strBuild);
return(strBuild.ToString());
}
/// <summary>
/// Computes the "sum" that each row/column/diagonal must add up to.
/// </summary>
/// <param name="values">
/// All the possible values for the magic square. Each value must be unique.
/// </param>.
/// <exception cref="ArgumentException">
/// Thrown if no sum is possible.
/// </exception>
public static int ComputeSum(ReadOnlySpan <int> values)
{
int boxSize = Boxes.IntSquareRoot(values.Length);
return(_ComputeSum(values, boxSize));
}