def a_star(start, end):
location = Location.get_instance()
open_set = {start}
came_from = dict()
gscore = {coord: 100000 for coord in location.get_valid_for_ghosts_coords()}
fscore = dict(gscore) # copy of this dict
gscore[start] = 0
fscore[start] = h(start, end)
while len(open_set) > 0:
# get the coordinate with the lowest value
current = min(open_set, key=lambda x: fscore[x])
if current == end:
return get_first_step(start, came_from, end)
open_set.remove(current)
for neighbour in [coord for coord in current.get_neighbours()]:
tentative_gScore = gscore[current] + 1
if tentative_gScore < gscore[neighbour]:
came_from[neighbour] = current
gscore[neighbour] = tentative_gScore
fscore[neighbour] = gscore[neighbour] + h(neighbour, end)
if neighbour not in open_set:
open_set.add(neighbour)
def move(self, movement):
locations = Location.get_instance()
next_coord = Coordinate(self.location.x, self.location.y)
next_coord.go_in_direction(movement)
if not Movement.inverses(
self.movement,
movement) and locations.is_valid_for_ghosts(next_coord):
self.movement = movement
super().move(self.movement)
