private static bool RecursiveSolve(SudokuPuzzle sudoku, int row, int column, ref int count, bool findMultiple = false)
{
if (sudoku[row, column] != 0)
{
return(SudokuSolver.RecursiveSolveNextNumber(sudoku, row, column, ref count, findMultiple));
}
List <int> possible = new List <int>();
for (int i = 1; i <= sudoku.Size; i++)
{
if (!(sudoku.RowContains(row, i) || sudoku.ColumnContains(column, i) || sudoku.BlockContains(row, column, i)))
{
possible.Add(i);
}
}
SudokuSolver.ShuffleNumbers(possible);
while (possible.Count > 0)
{
sudoku[row, column] = possible[0];
bool solvable = SudokuSolver.RecursiveSolveNextNumber(sudoku, row, column, ref count, findMultiple);
if (solvable)
{
if (!findMultiple || count > 1)
{
return(true);
}
}
possible.RemoveAt(0);
}
sudoku[row, column] = 0;
return(false);
}