private static void RaiseBreakerProgressEvent(SudokuPuzzle puzzle)
{
if (BreakerProgressEvent != null)
{
BreakerProgressEvent(new BreakerProgressEventArgs(puzzle));
}
}
private static void CopyPuzzle(SudokuPuzzle fromPuzzle, SudokuPuzzle toPuzzle)
{
foreach (SudokuCell cell in toPuzzle.Cells)
{
cell.SetPossibleValues(fromPuzzle.Cells[cell.X, cell.Y].PossibleValues);
}
}
public static bool TryBreak(SudokuPuzzle puzzle)
{
if (puzzle.IsSolved)
{
return(true);
}
if (puzzle.Failed)
{
return(false);
}
SudokuCell cellToTry = puzzle.GetFirstUnsolvedCell();
foreach (int possible in cellToTry.PossibleValues)
{
SudokuPuzzle puzzleTotry = new SudokuPuzzle(puzzle.ToIntArray());
SudokuCell cell = puzzleTotry.Cells[cellToTry.X, cellToTry.Y];
cell.SolvedValue = possible;
if (puzzleTotry.IsSolved)
{
CopyPuzzle(puzzleTotry, puzzle);
return(true); // no progress needed, it will return puzzle
}
else
{
if (puzzleTotry.Failed)
{
puzzle.Cells[cell.X, cell.Y].RemoveValue(possible);
RaiseBreakerProgressEvent(puzzle);
if (cell.IsSolved)
{
return(TryBreak(puzzle));
}
}
else
{
//try another cell
if (TryBreak(puzzleTotry))
{
CopyPuzzle(puzzleTotry, puzzle);
RaiseBreakerProgressEvent(puzzle);
return(true);
}
else
{
puzzle.Cells[cell.X, cell.Y].RemoveValue(possible);
CopyPuzzle(puzzle, puzzleTotry);
RaiseBreakerProgressEvent(puzzle);
if (cell.IsSolved)
{
return(TryBreak(puzzle));
}
}
}
}
}
return(false);
}
public BreakerProgressEventArgs(SudokuPuzzle puzzle)
{
this.Puzzle = puzzle;
}
public static async Task <bool> TryBreakAsync(SudokuPuzzle puzzle)
{
bool t = await Task.Run(() => TryBreak(puzzle));
return(t);
}