和我之前遇到的问题一样,我正在尝试创建一个广度优先搜索算法,它可以接受一个图并输出顶点访问顺序。它以邻接矩阵(表示图)作为输入,以下是我的进展。
import sys
import Queue
# Input has to be adjacency matrix or list
graphAL2 = {0 : [1,2,3],
1 : [0,3,4],
2 : [0,4,5],
3 : [0,1,5],
4 : [1,2],
5 : [2,3] }
# NEED TO FIX:
# - Final graphAL2v print is only displaying key values as 1, not iterating
# through graph and visiting each vertex
def main():
count = 0
graphAL2v = {}
for key, value in graphAL2.items():
graphAL2v[key] = 0
print(graphAL2v)
for key in graphAL2v: # each vertex v in V
if graphAL2v[key] == 0: # is marked with 0
bfs(key, count, graphAL2, graphAL2v)
print(graphAL2v)
def bfs(v, count, graphal, graphv):
count = count + 1
print('Visiting', v)
# Mark v with count and initialize queue with v
graphv[v] = count
visited = Queue.Queue()
while not visited.empty(): #queue not empty:
print('queue is not empty')
for element in graphal[v]: # each vertex w in V adjacent to front vertex
if element == 0:
count = count + 1
# mark w with count
graphal[v] = count
visited.put()
visited.get()
if __name__ == '__main__':
sys.exit(main())
我遇到的问题是我的输出结果
{0: 0, 1: 0, 2: 0, 3: 0, 4: 0, 5: 0}
('Visiting', 0)
('Visiting', 1)
('Visiting', 2)
('Visiting', 3)
('Visiting', 4)
('Visiting', 5)
{0: 1, 1: 1, 2: 1, 3: 1, 4: 1, 5: 1}
当它遍历“图形”时,对于列表中的所有顶点,将访问顺序显示为1,而不是为每个顶点显示不同的数字。我认为这个错误源于bfs()函数的while循环内部。有没有什么建议可以修复代码,以便我可以实现期望的输出?我也不太熟悉Python中的队列,所以任何帮助都会感激。