private static SodukuBoard CalculatePossibleValues(SodukuBoard board)
{
board = CalculatePossibleValuesForRows(board);
board = CalculatePossibleValuesForColumns(board);
board = CalculatePossibleValuesForGrids(board);
return(board);
}
public static SodukuBoard Solve(SodukuBoard board)
{
board.CheckSolved();
if (board.IsSolved)
{
return(board);
}
board = CalculatePossibleValues(board);
Cell cell = SelectCellWithFewestPossibleValues(board);
if (!cell.IsSet && cell.PossibleValues.Length == 0)
{
return(board);
}
for (int i = 0; i < cell.PossibleValues.Length; i++)
{
SodukuBoard child = (SodukuBoard)board.Clone();
child.SetCell(cell.Id, int.Parse(cell.PossibleValues.Substring(i, 1)));
child = Solve(child);
if (child.CheckSolved())
{
board = child.Clone() as SodukuBoard;
break;
}
}
return(board);
}
private static Cell SelectCellWithFewestPossibleValues(SodukuBoard board)
{
IQueryable <Cell> ordered = board.Cells.AsQueryable()
.Where(c => !c.IsSet)
.OrderBy(c => c.PossibleValues.Length);
return((Cell)ordered.First());
}
private static SodukuBoard CalculatePossibleValuesForRows(SodukuBoard board)
{
for (int i = 0; i < 9; i++)
{
CellGroup row = board.GetRow(i);
row.SetPossibleValues();
}
return(board);
}
private static SodukuBoard CalculatePossibleValuesForColumns(SodukuBoard board)
{
for (int i = 0; i < 9; i++)
{
CellGroup column = board.GetColumn(i);
column.SetPossibleValues();
}
return(board);
}
private static SodukuBoard CalculatePossibleValuesForGrids(SodukuBoard board)
{
for (int i = 0; i < 9; i++)
{
CellGroup grid = board.GetGrid(i);
grid.SetPossibleValues();
}
return(board);
}
public object Clone()
{
SodukuBoard clone = new SodukuBoard();
clone.IsSolved = this.IsSolved;
for (int i = 0; i < this.Cells.Length; i++)
{
clone.Cells[i] = Cells[i].Clone() as Cell;
}
return(clone);
}
