void UpdateCombinationsRemaining()
{
BigInteger numCombos = 1;
for (int row = 0; row < 9; row++)
{
for (int column = 0; column < 9; column++)
{
List <int> numbers = BaseGroupSolver.GetNumbers(SudokuBoard.squares[row, column].Notes);
if (numbers.Count > 0)
{
numCombos *= numbers.Count;
}
}
}
if (numCombos == 1)
{
numCombos = 0;
}
bool weHaveAReasonableNumberOfCombosWeCanSolve = numCombos < 200_000_000;
bool shouldEnableSolveButtons = alwaysEnableSolveButtons || weHaveAReasonableNumberOfCombosWeCanSolve;
btnBruteForce.IsEnabled = shouldEnableSolveButtons;
btnHint.IsEnabled = shouldEnableSolveButtons;
Title = $"The number of combinations is {numCombos}!";
}
bool BruteForceAttack(int startingRow = 0, int startingColumn = 0)
{
if (startingColumn >= 9)
{
startingColumn = 0;
startingRow++;
}
for (int row = startingRow; row < 9; row++)
{
for (int column = startingColumn; column < 9; column++)
{
startingColumn = 0;
ISudokuSquare sudokuSquare = SudokuBoard.squares[row, column];
if (!sudokuSquare.IsEmpty)
{
continue;
}
// Magic - I have an empty square!!!
if (sudokuSquare.Notes == "")
{
ShowNotesForSquareAt(sudokuSquare);
if (sudokuSquare.Notes == "") // That means we have a conflict.
{
return(BruteForceAttack(row, column + 1));
}
}
List <int> notes = BaseGroupSolver.GetNumbers(sudokuSquare.Notes);
foreach (int number in notes)
{
sudokuSquare.Value = number.ToString()[0];
sudokuSquare.HasTestValue = true;
numCombinationsTried++;
if (HasConflicts(row, column))
{
sudokuSquare.Value = Char.MinValue;
sudokuSquare.HasTestValue = false;
}
else if (BruteForceAttack(row, column + 1))
{
sudokuSquare.Notes = "";
return(true);
}
else
{
sudokuSquare.Value = Char.MinValue;
sudokuSquare.HasTestValue = false;
}
}
return(false);
}
}
return(AllSquaresAreFilled());
}
