public List <SmallSquare> GetAllPossibleSquares(List <SmallSquare> listOfSquares, int xPosition, int yPosition, HashSet <string> invalidFields, int smallSquareNumber)
{
int elementCounter = 0;
if (listOfSquares.Count == 0)
{
listOfSquares.Add(this);
}
if (yPosition == 3)
{
System.Diagnostics.Debug.WriteLine("GetAllPossibleSquares return");
Dictionary <string, SmallSquare> newList = new Dictionary <string, SmallSquare>();
foreach (SmallSquare sq in listOfSquares)
{
bool isOK = true;
if (smallSquareNumber < 6)
{
for (int y = 0; y < 3; y++)
{
for (int x = 0; x < 3; x++)
{
if (!sq.Fields[y, x].IsFixed)
{
if (invalidFields.Contains(SudokuSolver.GetBlockListEntry(smallSquareNumber, sq.Fields[y, x].FieldValue, x, y)))
{
isOK = false;
break;
}
}
if (!isOK)
{
break;
}
}
}
}
if (isOK && sq.IsComplete())
{
if (!newList.ContainsKey(sq.GetKey()))
{
newList.Add(sq.GetKey(), sq);
}
}
}
if (!newList.Any())
{
System.Diagnostics.Debug.WriteLine("no results");
}
return(newList.Select(val => val.Value).ToList());
}
Dictionary <string, SmallSquare> newSquares = new Dictionary <string, SmallSquare>();
foreach (SmallSquare existingSquare in listOfSquares)
{
elementCounter = 0;
for (int x = 0; x < 9; x++)
{
SmallSquare newSquare = Program.DeepClone(existingSquare);
HashSet <int> availableNumbers = newSquare.GetNumbersStillAvailable();
if (newSquare.Fields[yPosition, xPosition].IsFixed == false)
{
newSquare.Fields[yPosition, xPosition].FieldValue = availableNumbers.ElementAt(elementCounter);
elementCounter++;
}
if (!newSquares.ContainsKey(newSquare.GetKey()))
{
newSquares.Add(newSquare.GetKey(), newSquare);
}
if (availableNumbers.Count() == elementCounter)
{
break;
}
}
}
if (xPosition == 2)
{
xPosition = 0;
yPosition++;
}
else
{
xPosition++;
}
return(GetAllPossibleSquares(newSquares.Select(val => val.Value).ToList(), xPosition, yPosition, invalidFields, smallSquareNumber));
}
