def visible_neighbors(seats: SeatMap,
origin: Point) -> typing.List[SeatStatus]:
directions = Point.directions8
statuses = []
for x, y in directions:
for magnitude in itertools.count(1):
dx, dy = x * magnitude, y * magnitude
p = origin.displace(dx, dy)
if p not in seats:
break
if seats[p] != SeatStatus.Floor:
statuses.append(seats[p])
break
return statuses
class Explorer:
def __init__(self, tape):
self.tape = tape
self.position = Point(0, 0)
self.graph = collections.defaultdict(set)
self.oxygen = None
def explore(self):
places_to_visit = collections.deque([self.position])
visited = {self.position}
while places_to_visit:
next_point = places_to_visit.pop()
self.move_to(next_point)
unvisited_neighbors = set(self.position.neighbors()) - visited
for neighbor in unvisited_neighbors:
status = self.explore_adjacent_point(neighbor)
if status == StatusCode.Wall:
visited.add(neighbor)
if status in [StatusCode.Step, StatusCode.Oxygen]:
self.graph[self.position].add(neighbor)
self.graph[neighbor].add(self.position)
places_to_visit.append(neighbor)
if status == StatusCode.Oxygen:
self.oxygen = neighbor
visited.add(self.position)
def find_path(self, start, end):
import heapq as h
distances = {start: 0}
heap = [(0, start)]
prev_node = dict()
while end not in prev_node:
weight, node = h.heappop(heap)
unvisited_neighbors = self.graph[node] - distances.keys()
for neighbor in unvisited_neighbors:
prev_node[neighbor] = node
distance = weight + 1
distances[neighbor] = weight
h.heappush(heap, (distance, neighbor))
cur_node = end
path = [end]
while cur_node != start:
previous_node = prev_node[cur_node]
path.append(previous_node)
cur_node = previous_node
return list(reversed(path))[1:]
def distances_from(self, start):
import heapq as h
distances = {start: 0}
heap = [(0, start)]
while heap:
weight, node = h.heappop(heap)
unvisited_neighbors = self.graph[node] - distances.keys()
for neighbor in unvisited_neighbors:
distance = weight + 1
distances[neighbor] = weight
h.heappush(heap, (distance, neighbor))
return distances
def move_direction(self, direction):
input_code = direction_to_int(direction)
status_code = self.tape.run_until_output(provide_input=input_code)[0]
status = StatusCode(status_code)
if status != StatusCode.Wall:
self.position = self.position.displace(*direction.value)
return status
def move_to(self, destination):
if self.position == destination:
return
for point in self.find_path(self.position, destination):
self.move_direction(self.position.direction_to(point))
def explore_adjacent_point(self, point):
direction = self.position.direction_to(point)
status = self.move_direction(direction)
if status != StatusCode.Wall:
self.move_direction(direction.inverse_direction())
return status