def get_attackers(board, square, color):
retval = []
for name, pos in chess.Pieces(board, color):
if chess.LUT.att[name][pos][square] and \
(chess.LUT.btw[pos][square] & board.interferers).is_zero():
retval.append((name, pos))
return retval
def check(problem, board, solution):
visitor = FinalesVisitor()
solution.traverse(board, visitor)
if len(visitor.by_hash) > 0:
problem['pure-finales'] = [key for key in visitor.by_hash]
retval = {}
for keyword in provides():
retval[keyword] = False
mm, msm, im, ism = 0, 0, 0, 0
for dif in visitor.different:
mm_, msm_, im_, ism_ = 0, 0, 0, 0
for info in visitor.different[dif]:
if info['model'] and info['stale']:
msm_ = 1
if info['model'] and not info['stale']:
mm_ = 1
if info['ideal'] and info['stale']:
ism_ = 1
if info['ideal'] and not info['stale']:
im_ = 1
if info['octet']:
retval['Octet'] = True
if info['pins'] > 0:
retval['Models with pin'] = True
if info['pins'] > 1:
retval['Models with two pins'] = True
if info['pins'] > 2:
retval['Models with three pins'] = True
mm, msm, im, ism = mm + mm_, msm + msm_, im + im_, ism + ism_
retval['Model mates'], retval['Model stalemates'], retval[
'Ideal mates'], retval[
'Ideal satelemates'] = mm > 1, msm > 1, im > 1, ism > 1
if retval['Model mates']:
octet = ''
for piece, pos in chess.Pieces(board, chess.WHITE):
if piece in 'QRSB':
octet = octet + piece
retval['Octet'] = ''.join(sorted(octet)) == 'BBQRRSS'
# now echoes
for hash in visitor.by_hash:
if len(visitor.by_hash[hash]) < 2:
continue
for info1, info2 in common.tuples(visitor.by_hash[hash], 2, False):
if info1['mated'] != info2['mated'] or info1['traversal'] != info2[
'traversal']:
retval['Echo'] = True
if square_color(info1['mated']) != square_color(info2['mated']):
retval['Chameleon echo'] = True
return retval
def _analyze(board, mated):
retval = {
'ideal': False,
'model': False,
'pure': False,
'hash': 0,
'traversal': -1,
'mated': board.kings[mated],
'octet': False,
'pins': 0
}
mating = [chess.WHITE, chess.BLACK][mated == chess.WHITE]
mated_king = 'kK'[mated == chess.WHITE]
participants, attackers = chess.BitBoard(), {}
king_area = chess.BitBoard(
chess.LUT.att[mated_king][board.kings[mated]].v[0],
chess.LUT.att[mated_king][board.kings[mated]].v[1])
king_area[board.kings[mated]] = 1
for square in chess.SetBits(king_area):
attackers[square] = get_attackers(board, square, mating)
if len(attackers[square]) > 1:
return retval
if len(attackers[square]) == 1:
participants[attackers[square][0][1]] = 1
if square == board.kings[mated]:
continue
blocker = board.board[square][chess.NAME]
if (blocker == '') or chess.Board.is_of(blocker, mating):
continue
participants[square] = 1
# both blocked & once attacked => need to check pinning
if (len(attackers[square]) == 1):
if not chess.LUT.btw[attackers[square][0][1]][
board.kings[mated]][square]:
return retval
# checking that mate exploits pinning - black must have legal moves
# if pinner is removed
# nice bug: bk is transparent!
board.interferers[board.kings[mated]] = 1
id = board.board[attackers[square][0][1]][chess.ID]
board.drop(attackers[square][0][1])
if not board.has_legal_moves(mated):
board.add(attackers[square][0][0], attackers[square][0][1], id)
board.interferers[board.kings[mated]] = 0
return retval
board.interferers[board.kings[mated]] = 0
board.add(attackers[square][0][0], attackers[square][0][1], id)
retval['pins'] = retval['pins'] + 1
retval['model'], retval['pure'] = True, True
for name, pos in chess.Pieces(board, mating):
if (not name in ['pk', 'PK'
][mating == chess.WHITE]) and (not participants[pos]):
retval['model'] = False
break
retval['ideal'] = retval['model'] and (participants == board.interferers)
# checking unit has id = 0
init_id_map, retval['hash'] = {}, 999999999999
if len(attackers[board.kings[mated]]) > 0:
init_id_map[attackers[board.kings[mated]][0][1]] = 0 # checking unit
# id of other participants depend on traversal
for i in xrange(len(traversals)):
# if i <> 2: continue
id_map, hash, pinmask, next_id = copy.deepcopy(init_id_map), 0, 0, 1
for j in xrange(len(traversals[i])):
participant_id = -1
square = add(board.kings[mated], traversals[i][j])
if -1 == square: # board edge
id_map, participant_id, next_id = inc_id(id_map, -1, next_id)
elif board.board[square][chess.NAME] != '' and \
chess.Board.is_of(board.board[square][chess.NAME], mated): # blocked
# blockers have same id as board edge
id_map, participant_id, next_id = inc_id(id_map, -1, next_id)
if len(attackers[square]) > 0: # additionally pinned
pinmask = pinmask | (1 << j)
else: # the square is once attacked
id_map, participant_id, next_id = inc_id(
id_map, attackers[square][0][1], next_id)
hash = (hash << 3) + participant_id
hash = hash | (pinmask << 24)
if int(hash) < int(retval['hash']):
retval['hash'] = hash
retval['traversal'] = i
if retval['hash'] == 2739136:
retval['hash'] = 0
return retval