private void BuildJumpSequences(Figure figure, MoveSequence sequence, List <MoveSequence> builder)
{
if (ShouldPromoteKing(figure, board.Size))
{
sequence.Add(MoveStep.King());
builder.Add(sequence); //abort sequence traversing
return;
}
var endOfSequence = true;
foreach (var direction in GetDirections(figure))
{
var position = GetJumpPoint(figure, direction, out var neighbour);
if (position == Point.Nop)
{
continue;
}
if (sequence.Contains(position))
{
continue;
}
endOfSequence = false;
var figureAfterJump = new Figure(position, figure.Side, figure.IsKing);
var newSequence = new MoveSequence(sequence);
newSequence.Add(MoveStep.Jump(figureAfterJump.Point));
BuildJumpSequences(figureAfterJump, newSequence, builder);
}
if (endOfSequence && !sequence.IsEmpty)
{
builder.Add(sequence);
}
}
private void BuildSimpleMoves(Figure figure, List <MoveSequence> simpleMoves)
{
foreach (var direction in GetDirections(figure))
{
var jump = GetJumpPoint(figure, direction, out var neighbour);
if (jump == Point.Nop && neighbour.Side == Side.Empty)
{
var sequence = new MoveSequence(MoveStep.Move(neighbour.Point));
if (!figure.IsKing && ShouldPromoteKing(new Figure(neighbour.Point, figure.Side, figure.IsKing), board.Size))
{
sequence.Add(MoveStep.King());
}
simpleMoves.Add(sequence);
}
}
}
public bool Equals(MoveSequence other) => _set.SetEquals(other._set);
internal MoveSequence(MoveSequence sequence) : this()
{
_set = new HashSet <Point>(sequence._set);
_sequence = new LinkedList <MoveStep>(sequence._sequence);
}