private static void DoTheGuess()
{
bool broken = false;
int attempt = 1;
for (int i = 2; !broken; i++)
{
foreach (SudokuPiece piece in Sudoku.Pieces)
{
if (!piece.IsFilled)
{
if (piece.PossibleNumbers.Count == i)
{
Backup.SetBackup(piece);
piece.InsertValue(piece.PossibleNumbers.First());
broken = true;
break;
}
}
}
}
while (!Solve())
{
SudokuPiece changedPiece = Backup.RestoreLatestBackup();
changedPiece.InsertValue(changedPiece.PossibleNumbers.ElementAt(attempt));
attempt++;
}
Backup.DeleteLatestBackup();
}
public static void SetBackup(SudokuPiece changedPiece)
{
BackupData backup = new BackupData(Sudoku.PiecesFilled, changedPiece);
for (int i = 0; i < 81; i++)
{
if (Sudoku.Pieces[i].IsFilled)
{
backup.PiecesFilled.Add(i, Sudoku.Pieces[i].Value);
}
else
{
List <string> possibleNumbers = new List <string>();
possibleNumbers.AddRange(Sudoku.Pieces[i].PossibleNumbers);
backup.PiecesUnfilled.Add(i, possibleNumbers);
}
}
BackupDataStack.Push(backup);
}
public BackupData(int piecesToBackup, SudokuPiece changedPiece)
{
ChangedPiece = changedPiece;
PiecesFilled = new Dictionary <int, string>(piecesToBackup);
PiecesUnfilled = new Dictionary <int, List <string> >(81 - piecesToBackup);
}