def get_shortest_path(self, start, end, avoid):
if start == end: return end
if self.is_wall(start) or self.is_wall(end): return None
queue = PriorityQueue()
queue.add(start, 0)
inverted_tree = {}
movement_costs = {}
inverted_tree[start] = None
movement_costs[start] = 0
while not queue.is_empty():
current = queue.poll()
neighbours = self.get_neighbours(current)
for direction in Direction.ORDERED_DIRECTIONS:
neighbour = neighbours[direction]
if self.is_wall(neighbour) or (avoid and (neighbour in avoid)):
continue
cost = movement_costs[current] + 1
if (neighbour not in movement_costs) or (
cost < movement_costs[neighbour]):
movement_costs[neighbour] = cost
queue.add(
neighbour, cost +
mod_taxi_cab_distance(neighbour, end, self.get_width(),
self.get_height()))
inverted_tree[neighbour] = current
if current == end:
path = []
cursor = end
peek_cursor = inverted_tree[cursor]
while peek_cursor:
path.append(cursor)
cursor = peek_cursor
peek_cursor = inverted_tree[cursor]
path.reverse()
return path
return None
def get_taxicab_distance(self, start, end):
return mod_taxi_cab_distance(start, end, self.width, self.height)
