def discovered_attack(puzzle: Puzzle) -> bool:
if discovered_check(puzzle):
return True
for node in puzzle.mainline[1::2][1:]:
if util.is_capture(node):
between = SquareSet.between(node.move.from_square,
node.move.to_square)
assert isinstance(node.parent, ChildNode)
if node.parent.move.to_square == node.move.to_square:
return False
prev = node.parent.parent
assert isinstance(prev, ChildNode)
if (prev.move.from_square in between
and node.move.to_square != prev.move.to_square
and node.move.from_square != prev.move.to_square
and not util.is_castling(prev)):
return True
return False
def castling(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2]:
if util.is_castling(node):
return True
return False