def __getitem__(self, node):
state_hash = self._get_hash(node)
if state_hash in self.nodes:
if node.state.player is None: return (0, self.nodes[state_hash][0])
found = (None, None)
for similar in self.nodes[state_hash]:
if similar.state.player is None: return (0, similar)
try:
grid = node.state.instance.get_grid_from_state(
similar.state)
path_search = GridSearchInstance(grid,
similar.state.player)
path_search_start = GridSearchState(
path_search, *node.state.player)
path = search.grid_search(
path_search, path_search_start,
search.AStarFringe(
ManhattanDistanceHeuristic(similar.state.player)))
if not found[1] or similar.cost + path.info[
"cost"] < found[1].cost:
found = (path.info["cost"], similar)
except search.SolutionNotFoundError:
continue
if found[1]: return found
raise IndexError()
def _dist(self, first, second):
try:
grid = self.instance.empty_grid
path_search = GridSearchInstance(grid, second)
path_search_start = GridSearchState(path_search, *first)
path = search.grid_search(
path_search, path_search_start,
search.AStarFringe(ManhattanDistanceHeuristic(second)))
return path.info["cost"]
except search.SolutionNotFoundError:
return float("inf")
def generate_neighbors(self, state):
neighbors = []
current_grid = self.get_grid_from_state(state)
available_boxes = self.boxes_to_consider.get(self.last_state, state,
current_grid)
for x, y in available_boxes:
for dx, dy in [(1, 0), (-1, 0), (0, 1), (0, -1)]:
old_player_pos = (x - dx, y - dy)
new_player_pos = (x, y)
box_pos = (x + dx, y + dy)
player_blocked = self._is_blocked(current_grid,
*old_player_pos)
box_blocked = self._is_blocked(current_grid, *box_pos)
if player_blocked or box_blocked:
continue
new_boxes = [(x_j, y_j) if (x_j, y_j) != (x, y) else
(x_j + dx, y_j + dy) for x_j, y_j in state.boxes]
neighbor = GameState(self, new_boxes, new_player_pos)
cost = 1
if state.player and state.player != old_player_pos:
neighbor_grid = self.get_grid_from_state(state)
path_search = GridSearchInstance(neighbor_grid,
state.player)
path_search_start = GridSearchState(
path_search, *old_player_pos)
try:
path = search.grid_search(
path_search, path_search_start,
search.AStarFringe(
ManhattanDistanceHeuristic(state.player)))
cost = path.info["cost"] + 1
except search.SolutionNotFoundError:
continue
try:
neighbor = self.states[neighbor]
except:
self.states[neighbor] = neighbor
neighbors.append((neighbor, cost))
return neighbors
def dist(self, first, second):
if first.player is None or second.player is None:
return 0
try:
grid = first.instance.get_grid_from_state(first)
path_search = GridSearchInstance(grid, second.player)
path_search_start = GridSearchState(path_search, *first.player)
path = search.grid_search(
path_search, path_search_start,
search.AStarFringe(ManhattanDistanceHeuristic(second.player)))
return path.info["cost"]
except search.SolutionNotFoundError:
return float("inf")
def solve_uni(instance, search_strategy):
solution = search.search(instance, instance.start, search_strategy, True)
for i in range(0, len(solution)):
print(solution[i].state, solution[i].cost)
current_grid = instance.get_grid_from_state(instance.goal)
path_search = GridSearchInstance(current_grid, solution[-1].state.player)
path_search_start = GridSearchState(path_search, *instance.goal.player)
path_to_start = search.grid_search(
path_search, path_search_start,
search.AStarFringe(
ManhattanDistanceHeuristic(solution[-1].state.player)))
solution.info["cost"] += path_to_start.info["cost"]
print(instance.goal, solution.info["cost"])
return solution
def __eq__(self, other):
for box in self.boxes:
if not box in other.boxes:
return False
if self.player and other.player:
current_grid = self.instance.get_grid_from_state(self)
path_search = GridSearchInstance(current_grid, self.player)
path_search_start = GridSearchState(path_search, other.player[0],
other.player[1])
try:
search.grid_search(
path_search, path_search_start,
search.AStarFringe(ManhattanDistanceHeuristic(
self.player)))
except search.SolutionNotFoundError:
return False
return True
def add(self, node):
state_hash = self._get_hash(node)
if state_hash in self.nodes and node.state.player is not None:
for similar in self.nodes[state_hash]:
if similar.state.player is None: return None
try:
grid = node.state.instance.get_grid_from_state(
similar.state)
path_search = GridSearchInstance(grid,
similar.state.player)
path_search_start = GridSearchState(
path_search, *node.state.player)
path = search.grid_search(
path_search, path_search_start,
search.AStarFringe(
ManhattanDistanceHeuristic(similar.state.player)))
except search.SolutionNotFoundError:
continue
return self.nodes[state_hash].append(node)