def a_star_search(problem, fringe):
# If there is no node on fringe, make one
if len(fringe.queue) <= 0:
initial_node = Node(problem)
fringe.insert(initial_node)
# If nodes don't have path cost for A* Search, give them one
for node in fringe.queue:
if node.a_star_cost == None:
node.a_star_cost = a_star_evaluator(node)
# Form a temporary priority queue
a_star_fringe = Queue()
a_star_fringe.insert_all(fringe.queue)
# Sort them according to lowest path cost
bubble_sort(a_star_fringe, False)
# Iterate over the sorted nodes, to check visually
for nodes in a_star_fringe.queue:
print('Node: ' + str(nodes.a_star_cost) + ' Depth: ' + str(nodes.depth) + ' Action: ' + str(nodes.action))
# Now do the good stuff
# Get the first node in A* fringe and then pop it on the main fringe
greed_node = a_star_fringe.pop()
node = fringe.pop_specific(greed_node)
# If the node is the goal, return it as goal; otherwise expand it
if goal_test(node.state) == True:
return True, solution(node), node
else:
if node.state.connor.death == False:
fringe.insert_all(expand(node))
return False, fringe, node
def best_fs(problem, fringe):
# If there is no node on fringe, make one
if len(fringe.queue) <= 0:
initial_node = Node(problem)
fringe.insert(initial_node)
# If nodes don't have path cost for Greedy BFS, give them one
for node in fringe.queue:
if node.greed_cost == None:
node.greed_cost = best_fs_evaluator(node)
# Form a temporary priority queue
best_fs_fringe = Queue()
best_fs_fringe.insert_all(fringe.queue)
# Sort them according to lowest path cost
bubble_sort(best_fs_fringe)
# Now do the good stuff
# Get the first node in Greedy BFS fringe and then pop it on the main fringe
greed_node = best_fs_fringe.pop()
node = fringe.pop_specific(greed_node)
# If the node is the goal, return it as goal; otherwise expand it
if goal_test(node.state) == True:
return True, solution(node), node
else:
if node.state.connor.death == False:
fringe.insert_all(expand(node))
return False, fringe, node
