private List <byte> EliminationSearch(IEnumerable <byte> rowColCellSearchSolutions)
{
var eliminationSearchSolutions = new List <byte>();
foreach (var recentlyFoundIndex in rowColCellSearchSolutions)
{
var eliminatedElements = new List <byte>();
// store digit for later
var digit = Sudoku[recentlyFoundIndex];
// Remove all line, col and cell entries (cannot go there again)
foreach (var removerIndex in
SudokuSolver.GetRowIterator(recentlyFoundIndex)
.Union(SudokuSolver.GetColIterator(recentlyFoundIndex))
.Union(SudokuSolver.GetCellIterator(recentlyFoundIndex))
)
{
var possibleSolutions = PossibilitySpace[removerIndex];
// Check if already set
if (possibleSolutions is null)
{
continue;
}
// Remove possibility
possibleSolutions.Remove(digit);
// check if only solution
if (possibleSolutions.Count == 1)
{
ProcessNewMatch(possibleSolutions.First(), (byte)removerIndex, ref eliminatedElements);
}
}
eliminationSearchSolutions.AddRange(eliminatedElements);
}
return(eliminationSearchSolutions);
}