private void _UpdateUniqueCoordinates(
BitVector possiblesToCheck,
ReadOnlySpan <Coordinate> coordinatesToCheck,
Dictionary <Coordinate, BitVector> previousPossibles)
{
Span <int> possibleValues = stackalloc int[_numPossibleValues];
int numPossible = possiblesToCheck.PopulateSetBits(possibleValues);
for (int i = 0; i < numPossible; ++i)
{
int possibleToCheck = possibleValues[i];
Coordinate?uniqueCoord = null;
foreach (Coordinate c in coordinatesToCheck)
{
if (_puzzle.GetPossibleValues(in c).IsBitSet(possibleToCheck))
{
if (uniqueCoord.HasValue)
{
uniqueCoord = null;
break;
}
uniqueCoord = c;
}
}
if (!uniqueCoord.HasValue)
{
continue;
}
var possibles = new BitVector();
possibles.SetBit(possibleToCheck);
previousPossibles[uniqueCoord.Value] = _puzzle.GetPossibleValues(uniqueCoord.Value);
_puzzle.SetPossibleValues(uniqueCoord.Value, possibles);
}
}
