/// <summary>
/// Reduce possibilities as low as possible
/// with known numbers in row/column/square
/// </summary>
public void Solve(object param)
{
Sudoku sudoku = (Sudoku)param;
int index = 0;
do
{
if (Solver.locker.Acquire(index))
{
if (sudoku.GetField(index).Value == 0)
{
List <int> toRemove = Solver.GetNumbersInSquare(index, sudoku);
List <int> horizontal = Solver.GetNumbersInRow(index, sudoku);
foreach (int v in horizontal)
{
if (!toRemove.Contains(v))
{
toRemove.Add(v);
}
}
List <int> vertical = Solver.GetNumbersInColumn(index, sudoku);
foreach (int v in vertical)
{
if (!toRemove.Contains(v))
{
toRemove.Add(v);
}
}
List <int> possibilities = sudoku.GetPossibilities(index);
foreach (int v in toRemove)
{
if (possibilities.Contains(v))
{
sudoku.RemovePossibility(index, v);
}
}
if (possibilities.Count == 1)
{
sudoku.Set(index, possibilities[0]);
sudoku.RemovePossibility(index, possibilities[0]);
}
}
Solver.locker.Release(index);
}
index = (index + 1) % Sudoku.SIZE;
} while (!Solver.IsSolved());
}
