public void SetValue(SudokuSquare s, int value)
{
s.SetValue(value);
foreach (var ss in AllRelated(s))
{
ss.Forbid(value);
}
}
public SudokuBoard()
{
board = new SudokuSquare[9, 9];
foreach (var r in SudokuIterators.Indexes)
{
foreach (var c in SudokuIterators.Indexes)
{
board[r, c] = new SudokuSquare {
Row = r, Column = c
};
}
}
}
/// <summary>
/// Set the values for the first square that has its options reduced to 1.
/// </summary>
public static bool SquareHasOneOption(this SudokuBoard board, out SudokuSquare newlySolved)
{
newlySolved = null;
foreach (var s in board.Squares)
{
if (s.HasValue)
{
continue;
}
if (s.NumOptions == 1)
{
board.SetValue(s, s.Options.Single());
newlySolved = s;
return(true);
}
}
return(false);
}
/// <summary>
/// If all squares in a group (row, column, block) but one exclude the same value, then the square without the
/// exclusion must be that value.
/// </summary>
public static bool GroupHasOneSquareWithOption(this SudokuBoard board, out SudokuSquare newlyFound)
{
newlyFound = null;
foreach (var enumerator in new[] { board.EnumerateRows(), board.EnumerateColumns(), board.EnumerateBlocks() })
{
foreach (var group in enumerator)
{
var unsetSquares = group.Where(s => !s.HasValue).ToList();
var unsetValues = group.UnfoundOptions();
foreach (var v in unsetValues)
{
if (unsetSquares.Count(e => e.Options.Contains(v)) == 1)
{
newlyFound = unsetSquares.Single(e => e.Options.Contains(v));
board.SetValue(newlyFound, v);
return(true);
}
}
}
}
return(false);
}
public bool IsRelatedTo(SudokuSquare s) => Row == s.Row || Column == s.Column || Block == s.Block;
public IEnumerable <SudokuSquare> AllRelated(SudokuSquare square) => Squares.Where(square.IsRelatedTo);
