public List <string> Evaluate(Grid grid, PencilMarks pencilMarks)
{
var result = new List <string>();
foreach (var row in grid.Rows())
{
var marks = row
.EmptyColumns()
.Select(c => pencilMarks.Marks(c, row.RowNumber))
.GroupBy(c => c)
.Where(c => c.Key.Count() > 1 && c.Count() == c.Key.Count());
foreach (var group in marks)
{
var subset = group.Key;
foreach (var columnNumber in row.EmptyColumns())
{
var marksInCell = pencilMarks.Marks(columnNumber, row.RowNumber);
if (!marksInCell.SequenceEqual(subset))
{
foreach (var digit in subset)
{
if (pencilMarks.TryRubOutMark(columnNumber, row.RowNumber, digit) > 0)
{
result.Add($"DisjointSubset (row) rubbed out {digit} from {columnNumber},{row.RowNumber}. Subset was {{{string.Join(',', subset)}}}");
}
}
}
}
}
}
return(result);
}
private static void RemoveMark(PencilMarks pencilMarks, char digit, List <string> results, int columnNumber, int rowNumber)
{
if (pencilMarks.TryRubOutMark(columnNumber, rowNumber, digit) > 0)
{
results.Add($"Using CandidateLines removed pencilmark {digit} from {columnNumber},{rowNumber}");
}
;
}
