def basic_dfs(graph, startNode, goalNode):
"""
Performs a depth-first search on a graph from a specified start
node to a specified goal node, returning a path-to-goal if it
exists, otherwise returning None.
Uses backtracking, but does not use an extended set.
"""
return generic_search()(graph, startNode, goalNode)
visited, stack = set(), [startNode]
while stack:
vertex = stack.pop()
if vertex not in visited:
if vertex is goalNode:
return make_generic_search(extensions,
has_loops)()(graph, startNode,
goalNode)
visited.add(vertex)
for n in graph.get_neighbors(vertex):
if n not in visited:
stack.append(n)
return None
ext=[]
neighbors=graph.get_neighbors(path[len(path)-1])
for n in neighbors:
if not(n in path):
copy=path[:]
copy.append(n)
ext.append(copy)
return ext
def sort_by_heuristic(graph, goalNode, nodes):
return sorted(sorted(nodes),key=lambda n: graph.get_heuristic_value(n, goalNode))
# You can ignore the following line. It allows generic_search (PART 3) to
# access the extensions and has_loops functions that you defined in PART 1.
generic_search = make_generic_search(extensions, has_loops) # DO NOT CHANGE
#### PART 2: Search Algorithms #########################################
# Note: Optionally, you may skip to Part 3: Generic Search,
# then complete Part 2 using your answers from Part 3.
def dfs(graph, startNode, goalNode):
return generic_search(*generic_dfs)(graph, startNode, goalNode)
def bfs(graph, startNode, goalNode):
return generic_search(*generic_bfs)(graph, startNode, goalNode)
def hill_climbing(graph, startNode, goalNode):
return generic_search(*generic_hill_climbing)(graph, startNode, goalNode)
for k in path:
j.append(k)
j.append(i)
if not has_loops(j):
n.append(j)
return break_ties(n)
def sort_by_heuristic(graph, goalNode, nodes):
k = sorted(nodes)
return sorted(k, key=lambda x: graph.get_heuristic_value(x, goalNode))
# You can ignore the following line. It allows generic_search (PART 3) to
# access the extensions and has_loops functions that you defined in PART 1.
generic_search = make_generic_search(extensions, has_loops) # DO NOT CHANGE
#### PART 2: Search Algorithms #########################################
# Note: Optionally, you may skip to Part 3: Generic Search,
# then complete Part 2 using your answers from Part 3.
def dfs(graph, startNode, goalNode):
return generic_search(*generic_dfs)(graph, startNode, goalNode)
def bfs(graph, startNode, goalNode):
return generic_search(*generic_bfs)(graph, startNode, goalNode)
'''agenda = [[startNode]]
notfound = True
temp_path.append(edge.endNode)
if not has_loops(temp_path):
new_paths.append(temp_path)
return sorted(new_paths)
def sort_by_heuristic(graph, goalNode, nodes):
temp_nodes = nodes[:]
temp_nodes = sorted(nodes)
return sorted(temp_nodes, key = lambda node: graph.get_heuristic_value(node, goalNode))
generic_search = make_generic_search(extensions, has_loops)
#### PART 2: Search Algorithms #########################################
def dfs(graph, startNode, goalNode):
paths = [[startNode]]
while True:
if paths[0][-1] == goalNode:
return paths[0]
extended_path = extensions(graph, paths[0])
paths[1:1] = extended_path
if len(paths) >= 2:
del(paths[0])
