def _wire_ends_from_rail_loc(self, loc, proto_board):
"""
Returns a list of the locations that can be connected by a wire with the
given |loc| on the given |proto_board|, assuming that |loc| is a rail
location.
"""
assert is_rail_loc(loc)
r, c = loc
# can draw vertical wires to every other location in the same column
wire_ends = [(new_r, c) for new_r in ROWS]
return filter(self._valid_not_occupied_filter(proto_board), wire_ends)
def _wire_ends_from_rail_loc(self, loc, proto_board):
"""
Returns a list of the locations that can be connected by a wire with the
given |loc| on the given |proto_board|, assuming that |loc| is a rail
location.
"""
assert is_rail_loc(loc)
r, c = loc
# can draw vertical wires to every other location in the same column
wire_ends = [(new_r, c) for new_r in ROWS]
return filter(self._valid_not_occupied_filter(proto_board), wire_ends)
def get_children(self):
children = []
proto_board, loc_pairs = self.state
for i, (loc_1, loc_2, resistor, node) in enumerate(loc_pairs):
# can extend a wire from |loc_1| towards |loc_2| from any of the
# the locations |loc_1| is internally connected to
for neighbor_loc in filter(proto_board.free,
proto_board.locs_connected_to(loc_1)):
# get candidate end locations for the new wire to draw
wire_ends = (self._wire_ends_from_rail_loc(neighbor_loc,
proto_board) if is_rail_loc(neighbor_loc) else
self._wire_ends_from_body_loc(neighbor_loc, proto_board,
span=dist(loc_1, loc_2)))
for wire_end in wire_ends:
# make sure that there is a wire to draw
if wire_end == neighbor_loc:
continue
new_wire = Wire(neighbor_loc, wire_end, node)
# track number of pieces this wire crosses
num_piece_crossings = sum(piece.crossed_by(new_wire) for piece in
proto_board.get_pieces())
if not ALLOW_PIECE_CROSSINGS and num_piece_crossings:
continue
# track number of other wires this new wire crosses
any_same_orientation_crossings = False
num_wire_crossings = 0
for wire in proto_board.get_wires():
if wire.crosses(new_wire):
if wire.vertical() == new_wire.vertical():
any_same_orientation_crossings = True
break
else:
num_wire_crossings += 1
# don't allow any wire crossings where the two wires have the same
# orientation
if any_same_orientation_crossings:
continue
# continue if we do not want to allow any crossing wires at all, even
# ones of different orientation
if not ALLOW_WIRE_CROSSINGS and num_wire_crossings:
continue
# construct a proto board with this new wire
wire_proto_board = proto_board.with_wire(new_wire)
# check that adding the wire is reasonable
wire_proto_board_valid = (wire_proto_board and wire_proto_board is
not proto_board)
# potentially create another proto board with a resistor in place of
# the new wire
add_resistor = (resistor is not None and not num_piece_crossings and
not num_wire_crossings and new_wire.length() == 3)
if add_resistor:
n1, n2, r, label = (resistor.n1, resistor.n2, resistor.r,
resistor.label)
# find representatives for the two nodes, they better be there
n1_group = proto_board.rep_for(n1)
assert n1_group
n2_group = proto_board.rep_for(n2)
assert n2_group
# check that wire loc 1 is in the same group as node n1
assert proto_board.rep_for(new_wire.loc_1) == n1_group
# find representative for wire loc 2, might not be there
wire_loc_2_group = proto_board.rep_for(new_wire.loc_2)
# if it is there, it better be the same as n2_group, or we can't put
# a resistor here
if (not wire_loc_2_group) or wire_loc_2_group == n2_group:
# figure out correct orientation of Resistor_Piece n1 and n2
vertical = new_wire.vertical()
if new_wire.c_1 < new_wire.c_2 or new_wire.r_1 < new_wire.r_2:
resistor_piece = Resistor_Piece(n1, n2, r, vertical, label)
resistor_piece.top_left_loc = new_wire.loc_1
else:
resistor_piece = Resistor_Piece(n2, n1, r, vertical, label)
resistor_piece.top_left_loc = new_wire.loc_2
# create proto board with resistor
new_proto_board = proto_board.with_piece(resistor_piece)
if not wire_loc_2_group:
# ensure to mark the oposite location with its apporpriate node
new_proto_board = new_proto_board.with_loc_repped(n2_group,
new_wire.loc_2)
# would no longer need a resistor for this pair of locations
new_resistor = None
# and the node for the rest of the wires will be the node for the
# other end of the resistor
new_node = n2
else:
# placing the resistor would create a violating connection
add_resistor = False
if not add_resistor:
if wire_proto_board_valid:
# can still put a wire down if allowed
new_proto_board = wire_proto_board
new_resistor = resistor
new_node = node
else:
continue
# we have a candidate proto board, compute state and cost
new_loc_pairs = list(loc_pairs)
new_cost = self.cost + new_wire.length()
if proto_board.connected(wire_end, loc_2):
new_loc_pairs.pop(i)
# favor connectedness a lot
new_cost -= 100
else:
new_loc_pairs[i] = (wire_end, loc_2, new_resistor, new_node)
# penalize long wires
new_cost += new_wire.length()
# penalize many wires
new_cost += 10
# penalize wires crossing pieces (if allowed at all)
new_cost += 1000 * num_piece_crossings
# penalize crossing wires of opposite orientation (if allowed at all)
new_cost += 1000 * num_wire_crossings
# favor wires that get us close to the goal, and penalize wires
# that get us farther away
new_cost += dist(wire_end, loc_2) - dist(loc_1, loc_2)
children.append(Proto_Board_Search_Node(new_proto_board,
frozenset(new_loc_pairs), self, new_cost,
self.filter_wire_lengths))
# if added a resistor, also create a proto board where we use a wire
# instead of the resistor
if add_resistor and wire_proto_board_valid:
wire_loc_pairs = list(loc_pairs)
wire_loc_pairs[i] = (wire_end, loc_2, resistor, node)
children.append(Proto_Board_Search_Node(wire_proto_board,
frozenset(wire_loc_pairs), self, new_cost,
self.filter_wire_lengths))
return children
def get_children(self):
children = []
proto_board, loc_pairs = self.state
for i, (loc_1, loc_2, resistor, node) in enumerate(loc_pairs):
# can extend a wire from |loc_1| towards |loc_2| from any of the
# the locations |loc_1| is internally connected to
for neighbor_loc in filter(proto_board.free,
proto_board.locs_connected_to(loc_1)):
# get candidate end locations for the new wire to draw
wire_ends = (
self._wire_ends_from_rail_loc(neighbor_loc, proto_board)
if is_rail_loc(neighbor_loc) else
self._wire_ends_from_body_loc(
neighbor_loc, proto_board, span=dist(loc_1, loc_2)))
for wire_end in wire_ends:
# make sure that there is a wire to draw
if wire_end == neighbor_loc:
continue
new_wire = Wire(neighbor_loc, wire_end, node)
# track number of pieces this wire crosses
num_piece_crossings = sum(
piece.crossed_by(new_wire)
for piece in proto_board.get_pieces())
if not ALLOW_PIECE_CROSSINGS and num_piece_crossings:
continue
# track number of other wires this new wire crosses
any_same_orientation_crossings = False
num_wire_crossings = 0
for wire in proto_board.get_wires():
if wire.crosses(new_wire):
if wire.vertical() == new_wire.vertical():
any_same_orientation_crossings = True
break
else:
num_wire_crossings += 1
# don't allow any wire crossings where the two wires have the same
# orientation
if any_same_orientation_crossings:
continue
# continue if we do not want to allow any crossing wires at all, even
# ones of different orientation
if not ALLOW_WIRE_CROSSINGS and num_wire_crossings:
continue
# construct a proto board with this new wire
wire_proto_board = proto_board.with_wire(new_wire)
# check that adding the wire is reasonable
wire_proto_board_valid = (wire_proto_board
and wire_proto_board
is not proto_board)
# potentially create another proto board with a resistor in place of
# the new wire
add_resistor = (resistor is not None
and not num_piece_crossings
and not num_wire_crossings
and new_wire.length() == 3)
if add_resistor:
n1, n2, r, label = (resistor.n1, resistor.n2,
resistor.r, resistor.label)
# find representatives for the two nodes, they better be there
n1_group = proto_board.rep_for(n1)
assert n1_group
n2_group = proto_board.rep_for(n2)
assert n2_group
# check that wire loc 1 is in the same group as node n1
assert proto_board.rep_for(new_wire.loc_1) == n1_group
# find representative for wire loc 2, might not be there
wire_loc_2_group = proto_board.rep_for(new_wire.loc_2)
# if it is there, it better be the same as n2_group, or we can't put
# a resistor here
if (not wire_loc_2_group
) or wire_loc_2_group == n2_group:
# figure out correct orientation of Resistor_Piece n1 and n2
vertical = new_wire.vertical()
if new_wire.c_1 < new_wire.c_2 or new_wire.r_1 < new_wire.r_2:
resistor_piece = Resistor_Piece(
n1, n2, r, vertical, label)
resistor_piece.top_left_loc = new_wire.loc_1
else:
resistor_piece = Resistor_Piece(
n2, n1, r, vertical, label)
resistor_piece.top_left_loc = new_wire.loc_2
# create proto board with resistor
new_proto_board = proto_board.with_piece(
resistor_piece)
if not wire_loc_2_group:
# ensure to mark the oposite location with its apporpriate node
new_proto_board = new_proto_board.with_loc_repped(
n2_group, new_wire.loc_2)
# would no longer need a resistor for this pair of locations
new_resistor = None
# and the node for the rest of the wires will be the node for the
# other end of the resistor
new_node = n2
else:
# placing the resistor would create a violating connection
add_resistor = False
if not add_resistor:
if wire_proto_board_valid:
# can still put a wire down if allowed
new_proto_board = wire_proto_board
new_resistor = resistor
new_node = node
else:
continue
# we have a candidate proto board, compute state and cost
new_loc_pairs = list(loc_pairs)
new_cost = self.cost + new_wire.length()
if proto_board.connected(wire_end, loc_2):
new_loc_pairs.pop(i)
# favor connectedness a lot
new_cost -= 100
else:
new_loc_pairs[i] = (wire_end, loc_2, new_resistor,
new_node)
# penalize long wires
new_cost += new_wire.length()
# penalize many wires
new_cost += 10
# penalize wires crossing pieces (if allowed at all)
new_cost += 1000 * num_piece_crossings
# penalize crossing wires of opposite orientation (if allowed at all)
new_cost += 1000 * num_wire_crossings
# favor wires that get us close to the goal, and penalize wires
# that get us farther away
new_cost += dist(wire_end, loc_2) - dist(loc_1, loc_2)
children.append(
Proto_Board_Search_Node(new_proto_board,
frozenset(new_loc_pairs), self,
new_cost,
self.filter_wire_lengths))
# if added a resistor, also create a proto board where we use a wire
# instead of the resistor
if add_resistor and wire_proto_board_valid:
wire_loc_pairs = list(loc_pairs)
wire_loc_pairs[i] = (wire_end, loc_2, resistor, node)
children.append(
Proto_Board_Search_Node(wire_proto_board,
frozenset(wire_loc_pairs),
self, new_cost,
self.filter_wire_lengths))
return children