def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
# TODO
#the node state represent person_id and action represents movie_id
node=Node(state=source,parent=None,action=None)
frontier=QueueFrontier()
frontier.add(node)
explored=[]
path=[]
while True:
if frontier.empty():
return None
new=frontier.remove()
if new.state==target:
while new.parent is not None:
path.append([new.action,new.state])
new=new.parent
return path[::-1]
explored.append(new.state)
for movie,actor in neighbors_for_person(new.state):
if actor not in explored and not frontier.contains_state(new.state):
frontier.add(Node(state=actor,action=movie,parent=new))
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
start = Node(state = source, parent = None, action = None)
frontier = QueueFrontier()
frontier.add(start)
explored = set()
while True:
if frontier.empty():
return None
node = frontier.remove()
if node.state == target:
solution = []
while node.parent is not None:
pair = (node.action, node.state)
solution.append(pair)
node = node.parent
solution.reverse()
return solution
explored.add(node.state)
for action, state in neighbors_for_person(node.state):
if not frontier.contains_state(state) and state not in explored:
child = Node(state=state, parent=node, action=action)
frontier.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
start = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
frontier.add(start)
examined = set()
path = []
while True:
if frontier.empty():
return None
node = frontier.remove()
examined.add(node.state)
neighbors = neighbors_for_person(node.state)
for starred, person in neighbors:
if person == target:
path.append((starred, person))
while node.parent is not None:
path.append((node.action, node.state))
node = node.parent
path.reverse()
return path
else:
if not frontier.contains_state(
person) and person not in examined:
child = Node(state=person, parent=node, action=starred)
frontier.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
start = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
frontier.add(start)
explored = set()
"""
check if the negihtbors have the target if do return
"""
while True:
# If nothing left in frontier, then no path
if frontier.empty():
return []
# Choose a node from the frontier
node = frontier.remove()
# Mark node as explored
explored.add(node.state)
# Add neighbors to frontier
for action, state in neighbors_for_person(node.state):
if not frontier.contains_state(state) and state not in explored:
child = Node(state=state, parent=node, action=action)
if child.state == target:
return return_paths(child)
frontier.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
# TODO
start = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
frontier.add(start)
explored = set()
while True:
if frontier.empty():
return None
node = frontier.remove()
explored.add(node.state)
for action, state in neighbors_for_person(node.state):
if not frontier.contains_state(state) and state not in explored:
child = Node(state=state, parent=node, action=action)
if child.state == target:
path = []
while child.parent is not None:
path.insert(0, (child.action, child.state))
child = child.parent
return path
else:
frontier.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
explore = set()
frontier = QueueFrontier()
#start = neighbors_for_person(source)
#for state in start:
node = Node(source, parent=None, id=source)
frontier.add(node)
while True:
if frontier.empty():
return None
node = frontier.remove()
explore.add(node.id)
if node.id == target:
parents = []
while node.parent is not None:
parents.append(node.state)
node = node.parent
parents.reverse()
return parents
for state in neighbors_for_person(node.id):
if not frontier.contains_state(id) and state[1] not in explore:
child = Node(state=state, parent=node, id=state[1])
frontier.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
if source == target:
return []
start = Node(source, None, None)
queue = QueueFrontier()
queue.add(start)
explored = set()
while True:
if queue.empty():
return None
node = queue.remove()
explored.add(node.state)
for action, state in neighbors_for_person(node.state):
if state == target:
path = []
path.insert(0, (action, state))
while node.parent is not None:
path.insert(0, (node.action, node.state))
node = node.parent
return path
if not queue.contains_state(state) and state not in explored:
queue.add(Node(state, node, action))
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
# TODO
start = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
frontier.add(start)
Explored = set()
while True:
if frontier.empty():
return None
node = frontier.remove()
Explored.add(node)
Neighbors = neighbors_for_person(node.state)
for movie_id, person_id in Neighbors:
if not frontier.contains_state(
person_id) and person_id not in Explored:
child = Node(state=person_id, parent=node, action=movie_id)
if child.state == target:
solution = []
while node.parent is not None:
solution.append((node.action, node.state))
node = node.parent
solution.append((child.action, child.state))
return solution
frontier.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
start = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
frontier.add(start)
while True:
if frontier.empty():
return None
curr = frontier.remove()
if curr.state == target:
actions = []
cells = []
while curr.parent: # is not None
actions.append(curr.action)
cells.append(curr.state)
curr = curr.parent
actions.reverse()
cells.reverse()
path = []
for i in range(len(actions)):
path.append((actions[i], cells[i]))
return path
for action, state in neighbors_for_person(curr.state):
if not frontier.contains_state(state):
child = Node(state=state, parent=curr, action=action)
frontier.add(child)
def shortest_path(source: int, target: int):
"""
Returns the shortest list of (movie_id, person_id) pairs that connect the person with id source to the person with id target.
If no possible path, returns None.
"""
node = Node(state=source) # state: person_id, action: movie_id
explored = set() # set of person_id
frontier = QueueFrontier()
frontier.add(node)
while (not frontier.empty()):
node = frontier.remove()
explored.add(node.state)
for action, state in neighbors_for_person(node.state):
if not frontier.contains_state(state) and state not in explored:
child = Node(state, node, action)
frontier.add(child)
if (child.state == target):
return recover(child)
return None
def shortest_path(self, source, target):
source = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
frontier.add(source)
while True:
if frontier.empty():
raise Exception("No solution")
node = frontier.remove()
self.num_explored += 1
if node.state == target:
actions = []
while node.parent is not None:
actions.append(node.action)
node = node.parent
actions.reverse()
return actions
self.explored.append(node.state)
for act in neighbors_for_person(node.state):
print(act)
actor = act[-1]
if not frontier.contains_state(
actor) and actor not in self.explored:
child = Node(state=actor, parent=node, action=act)
frontier.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
InitialNode = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
frontier.add(InitialNode)
explored = set()
while not (frontier.empty()):
node = frontier.remove()
explored.add(node.state)
neighbors = neighbors_for_person(node.state)
for movie, person in neighbors:
Next = Node(person, node, movie)
if person not in explored or not frontier.contains_state(person):
if person == target:
path = []
node = Next
while node.parent is not None:
path.append((node.action, node.state))
node = node.parent
path.reverse()
return path
frontier.add(Next)
return None
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
queue = QueueFrontier()
start = Node(state=source, parent=None, action=None)
queue.add(start)
explored = set()
while True:
if queue.empty():
return None
node = queue.remove()
if node.state == target:
path = []
while node.parent is not None:
path.append((node.action, node.state))
node = node.parent
path.reverse()
return path
explored.add(node.state)
neighbors = neighbors_for_person(node.state)
for action, state in neighbors:
if not action or not state:
return None
elif state not in explored and not queue.contains_state(state):
child = Node(state=state, parent=node, action=action)
queue.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
# Initialize Frontier and add source (as node)
moving_frontier = QueueFrontier()
start_node = Node(source, None, None)
moving_frontier.add(start_node)
# BDF
while not moving_frontier.empty():
current = moving_frontier.remove()
neighbors = neighbors_for_person(current.state)
for neighbor in neighbors:
if neighbor[1] == source:
continue
elif moving_frontier.contains_state(neighbor[1]):
continue
elif neighbor[1] == target:
return node_path(Node(neighbor[1], current, neighbor[0]))
else:
moving_frontier.add(Node(neighbor[1], current, neighbor[0]))
else:
return None
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
frontier = QueueFrontier()
frontier.add(Node(source, None, None))
explored = set()
if source == target:
raise Exception("source should not be target")
while True:
if frontier.empty():
return None
node = frontier.remove()
if node.state == target:
answer = []
while node.parent is not None:
answer.append((node.action, node.state))
node = node.parent
answer.reverse()
return answer
explored.add(node.state)
for movie_id, person_id in neighbors_for_person(node.state):
if (not frontier.contains_state(person_id)) and (person_id
not in explored):
child = Node(state=person_id, parent=node, action=movie_id)
frontier.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
path = []
node = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
if node.state == target:
return path
frontier.add(node)
explored = set()
while True:
if frontier.empty():
return None
node = frontier.remove()
explored.add(node.state)
for movie, person in neighbors_for_person(node.state):
if not frontier.contains_state(person) and person not in explored:
child = Node(state=person, parent=node, action=movie)
if child.state != target:
frontier.add(child)
else:
while child.parent is not None:
path.append((child.action, child.state))
child = child.parent
path.reverse()
return path
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
start = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
frontier.add(start)
visited_nodes = set()
while True:
if frontier.empty():
raise Exception("no solution could be found")
node = frontier.remove()
visited_nodes.add(node)
if node.state == target:
path = []
while node.parent is not None:
path.append((node.action, node.state))
node = node.parent
path.reverse()
return path
for action, state in neighbors_for_person(node.state):
if not frontier.contains_state(
state) and state not in visited_nodes:
child = Node(state=state, parent=node, action=action)
frontier.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
# init frontier
srcNode = Node(source, None, None)
frontier = QueueFrontier()
frontier.add(srcNode)
visited = set()
while True:
if frontier.empty(): return None
# pop off current node
curNode = frontier.remove()
# add surrounding neighbors
for action, state in neighbors_for_person(curNode.state):
if not frontier.contains_state(state) and state not in visited:
childNode = Node(state, curNode, action)
# check for goal
if childNode.state == target:
path = []
while childNode.parent is not None:
path.append((childNode.action, childNode.state))
childNode = childNode.parent
path.reverse()
return path
else:
frontier.add(childNode)
visited.add(curNode.state)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
# TODO
queue = QueueFrontier()
start = Node(source, None, None)
queue.add(start)
explored = set()
while True:
if queue.empty():
return None
node = queue.remove()
explored.add(node.state)
for movie, person in neighbors_for_person(node.state):
if not queue.contains_state(person) and person not in explored:
child = Node(person, node, (movie, person))
if child.state == target:
return backtrack(child)
queue.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
explored = set()
frontier = QueueFrontier()
node = Node(source, None, None)
frontier.add(node)
while 1:
if (frontier.empty()):
return None
else:
node = frontier.remove()
if (node.state == target):
# Return the list
path = []
while node.parent:
path.append((node.action, node.state))
node = node.parent
path.reverse()
return path
else:
# Add the removed node to the explored set
explored.add(node)
# Add all the neighbors to the frontier if they have not been explored and they are not in the frontier yet
neighbors = neighbors_for_person(node.state)
for neighbor in neighbors:
newNode = Node(neighbor[1], node, neighbor[0])
if (not (frontier.contains_state(newNode.state)
or any(oldNode.state == newNode.state
for oldNode in explored))):
frontier.add(newNode)
def shortest_path(source, target):
solution = []
if source == target:
return solution
start = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
frontier.add(start)
explored = set()
while True:
if frontier.empty():
return None
node = frontier.remove()
explored.add(node.state)
for action, state in neighbors_for_person(node.state):
child = Node(state=state, parent=node, action=action)
if child.state == target:
while child.parent is not None:
solution.append((child.action, child.state))
child = child.parent
solution.reverse()
return solution
if not frontier.contains_state(state) and state not in explored:
frontier.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
q = QueueFrontier()
seen = set()
start = Node(state=source, parent=None, action=None)
q.add(start)
seen.add(start.state)
found_target = False
while not found_target:
if q.empty():
return None
temp_node = q.remove()
seen.add(temp_node.state)
if check_found(target, temp_node):
return check_found(target, temp_node)
for movie_id, actor_id in neighbors_for_person(temp_node.state):
if actor_id not in seen and not q.contains_state(actor_id):
child = Node(state=actor_id, parent=temp_node, action=movie_id)
if check_found(target, child):
return check_found(target, child)
q.add(child)
return None
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
frontier = QueueFrontier()
root_node = Node(source, None, None)
frontier.add(root_node)
return bfs(frontier, target)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
# Create a node with source as the initial state
start = Node(state=source, parent=None, action=None)
# Creating a empty queue frontier aka BFS
frontier = QueueFrontier()
# Adding the initial state to the frontier
frontier.add(start)
# Initialize an empty unexplored state
explored_state = set()
while True:
if frontier.empty():
return None
# Remove a node from the frontier
current_node = frontier.remove()
if current_node.state == target:
path = []
while current_node.parent is not None:
path.append((current_node.action, current_node.state))
current_node = current_node.parent
path.reverse()
return path
explored_state.add(current_node)
# A set of tuple of all the movies the current person is in and all stars starred in that movie
for movie, person in neighbors_for_person(current_node.state):
if not frontier.contains_state(
person) and person not in explored_state:
new_node = Node(state=person,
parent=current_node,
action=movie)
if new_node.state == target:
path = []
while new_node.parent is not None:
path.append((new_node.action, new_node.state))
new_node = new_node.parent
path.reverse()
return path
frontier.add(new_node)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
# TODO
# raise NotImplementedError
# Keep track of number of states explored
num_explored = 0
# Initialize frontier to just the starting position
start = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
frontier.add(start)
# Initialize an empty explored set
explored = set()
# Keep looping until solution found
while True:
# If nothing left in frontier, then no path
if frontier.empty():
raise Exception("no solution")
# Choose a node from the frontier
node = frontier.remove()
num_explored += 1
# If node is the goal, then we have a solution
if node.state == target:
actions = []
cells = []
solution = []
while node.parent is not None:
actions.append(node.action)
cells.append(node.state)
node = node.parent
actions.reverse()
cells.reverse()
for i in range(len(actions)):
solution.append((actions[i], cells[i]))
if len(solution) > 0:
return solution
else:
return None
# Mark node as explored
explored.add(node.state)
# Add neighbors to frontier
for action, state in neighbors_for_person(node.state):
if not frontier.contains_state(state) and state not in explored:
child = Node(state=state, parent=node, action=action)
frontier.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
num_explored = 0
# Initialize frontier to just the starting position
start = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
frontier.add(start)
# Initialize an empty explored set
explored = set()
# Keep looping until solution found
while True:
# If nothing left in frontier, then no path
if frontier.empty():
return None
# Choose a node from the frontier
node = frontier.remove()
num_explored += 1
# If node is the goal, then we have a solution
if node.state == target:
actions = []
cells = []
while node.parent is not None:
actions.append(node.action)
cells.append(node.state)
node = node.parent
actions.reverse()
cells.reverse()
solution = (actions, cells)
return
# Mark node as explored
explored.add(node.state)
# Add neighbors to frontier
for action, state in neighbors_for_person(node.state):
if state not in explored and not frontier.contains_state(action):
child = Node(state=state, parent=node, action=action)
if child.state == target:
action_path = []
node = child
while node.parent is not None:
action_path.append((node.action, node.state))
node = node.parent
action_path.reverse()
return action_path
frontier.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
neighbors = neighbors_for_person(source)
# Shortest path means BFS, then the frontier is a queue
frontier = QueueFrontier()
# Set of explored states
explored = set()
# Path to be returned (if any)
path = []
# Add all the actors staring with source in the frontier, with their movies
for neighbor in neighbors:
start = Node(state=neighbor, parent=None, action=None)
# If the source and the target stare in the same movie :
if target in start.state[1]:
path.append([start.state[0], start.state[1]])
return path
frontier.add(start)
while True:
# If there is no path
if frontier.empty():
return None
# Get a node from the fontier to be analyzed
node = frontier.remove()
explored.add(node.state)
for neighbor in neighbors_for_person(node.state[1]):
if not frontier.contains_state(
neighbor) and neighbor not in explored:
child = Node(state=neighbor, parent=node, action=None)
# If a path is found, add all the nodes to the variable path starting at the end (target -> source)
if target in child.state[1]:
node = child
while node.parent is not None:
path.append([node.state[0], node.state[1]])
node = node.parent
path.append([node.state[0], node.state[1]])
# Put back path in the right order (source -> target)
path.reverse()
return path
frontier.add(child)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
# TODO
# Keep track of number of states explored
num_explored = 0
# Initialize frontier to just the starting position
start = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
frontier.add(start)
explored = set()
# Keep looping until solution found
while True:
# If nothing left in frontier, then no path
if frontier.empty():
raise Exception("no solution")
# Choose a node from the frontier
node = frontier.remove()
num_explored += 1
# If node is the goal, then we have a solution
if node.state == target:
answer = []
while node.parent is not None:
#action = movieid, state = personid
answer.append((node.action, node.state))
node = node.parent
answer.reverse()
return answer
#Mark node as explored
if node.state not in explored:
explored.add(node.state)
for action, state in neighbors_for_person(node.state):
if not frontier.contains_state(state) and state not in explored:
child = Node(state=state, parent=node, action=action)
#if you detect a goal node, no need to add it to the frontier, you can simply return the solution immediately.
if child.state == target:
answer = []
while child.parent is not None:
#action = movieid, state = personid
answer.append((child.action, child.state))
child = child.parent
answer.reverse()
return answer
frontier.add(child)
explored.add(child.state)
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
# keep track of number of states explored
num_explored = 0
# state is person id
# action is movie id
# initialize frontier to starting position
start = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
frontier.add(start)
# initialize empty explored set
explored = set()
# keep looping until solution found
while True:
# if nothing in the frontier at start of loop, no path
if frontier.empty():
return (None)
# choose a node from the frontier
node = frontier.remove()
num_explored += 1
# if node is the goal, we have a solution
# this should be the shortest path since we're using BFS
if node.state == target:
actions = []
states = []
while node.parent is not None:
actions.append(node.action)
states.append(node.state)
node = node.parent
actions.reverse()
states.reverse()
solution = []
for i in range(len(actions)):
solution.append((actions[i], states[i]))
return (solution)
explored.add(node.state)
for action, state in neighbors_for_person(node.state):
if not frontier.contains_state(state) and state not in explored:
child = Node(state=state, parent=node, action=action)
frontier.add(child)
# TODO
raise NotImplementedError
def shortest_path(source, target):
"""
Returns the shortest list of (movie_id, person_id) pairs
that connect the source to the target.
If no possible path, returns None.
"""
#Initialize frontier to starting position
source = Node(state=source, parent=None, action=None)
frontier = QueueFrontier()
frontier.add(source)
#Explored Set
explored = set()
# TODO
#Solution Loop
while True:
if frontier.empty():
break
node = frontier.remove()
if node.state == target:
solution = []
while node.parent is not None:
segment = (node.action, node.state)
solution.append(segment)
node = node.parent
solution.reverse()
return solution
explored.add(node.state)
#add neighbors to frontier
neighbors = neighbors_for_person(node.state)
for costars in neighbors:
if costars[1] == target:
solution = []
finalnodes = Node(state=target, parent=node, action=costars[0])
while finalnodes.parent is not None:
segment = (finalnodes.action, finalnodes.state)
solution.append(segment)
finalnodes = finalnodes.parent
solution.reverse()
return solution
if not frontier.contains_state(
costars[1]) and costars[1] not in explored:
child = Node(state=costars[1], parent=node, action=costars[0])
frontier.add(child)
return None
raise NotImplementedError
