def breadth_search(self, initial_vertex):
for key in self.__adjacent_list:
if key != initial_vertex:
# seta cor branca p/ todos, menos o vertex inicial
key.set_color(0)
self.__distance[key] = float("inf")
self.__predecessors[key] = None
if not initial_vertex:
return self.__distance
initial_vertex.set_color(1) # seta cor do initial_vertex p cinza
self.__distance[initial_vertex] = 0
q = queue.Queue()
q.put(initial_vertex) # enfileiro o mocinho inicial
while not q.empty(): # enquanto a fila nao estiver vazia
vertex = q.get()
for v in self.__adjacent_list[vertex]:
if v.get_color() == 0: # igual a branco
v.set_color(1) # seta p/ cinza
self.__distance[v] = self.__distance[vertex] + 1
self.__predecessors[v] = vertex
q.put(v)
vertex.set_color(2) # seta p/ preto
return self.__distance
def __dfs_visit(self, vertex):
self.__time = self.__time + 1
self.__firstSee[vertex] = self.__time
vertex.set_color(1)
for adjacent in self.__adjacent_list[vertex]:
if adjacent.get_color() == 0:
self.__predecessors[adjacent] = vertex
self.__dfs_visit(adjacent)
vertex.set_color(2)
self.__time += 1
self.__close[vertex] = self.__time
def breadth_first_search(self, initial_vertex):
"""Calculate the distance of all vertex from one
if a vertex can't be reach by the initial vertex,
the distance will be infinity.. (float("inf"))
Args:
initial_vertex (Vetex): calculate the distance of
all vertices up to this initial vertex
Returns:
Dict: dictionaty with the key as the vertex and the body
the distance from the initial vertex
"""
# colors:
# white: not visited
# grey: in the queue
# black: nothing more to do
for key in self.__adjacent_list:
if key != initial_vertex:
# set color for all vertices except the initial one to white
key.set_color(0)
self.__distance[key] = float("inf")
self.__predecessors[key] = None
# if the initial_vertex is not a valid one,
# all the vertex will have distance equals to infinity
if not initial_vertex:
return self.__distance
initial_vertex.set_color(1) # inital vertex color to grey
self.__distance[initial_vertex] = 0
q = queue.Queue()
q.put(initial_vertex) # insert in the queue the initial vertex
while not q.empty():
vertex = q.get()
for v in self.__adjacent_list[vertex]:
if v.get_color() == 0: # if a vertex color is white
v.set_color(1) # turn to grey
self.__distance[v] = self.__distance[
vertex] + self.get_edge_from_souce_destination(
v, vertex).get_value()
self.__predecessors[v] = vertex
q.put(v)
vertex.set_color(2) # color to black
return self.__distance