python实现图的DFS和BFS
python实现图的DFS和BFS
DFS:
#定义一个图的结构
graph={
'A':['B','C'],
'B':['A','C','D'],
'C':['A','B','D','E'],
'D':['B','C','E','F'],
'E':['C','D'],
'F':['D']
}
def DFS(graph,s):
stack=[s]
seen={s}#检验是否遍历过
while 1:
if len(stack) > 0:
index = stack.pop()
for i in graph[index]:
if i not in seen:
stack.append(i)
seen.add(i)
print(index)
else:break
DFS(graph,"A")
BFS:
#定义一个图的结构
graph={
'A':['B','C'],
'B':['A','C','D'],
'C':['A','B','D','E'],
'D':['B','C','E','F'],
'E':['C','D'],
'F':['D']
}
def BFS(graph,s):
queue=[s]
seen={s}#检验是否遍历过
while 1:
if len(queue) > 0:
index = queue.pop(0)
for i in graph[index]:
if i not in seen:
queue.append(i)
seen.add(i)
print(index)
else:break
BFS(graph,"A")
所以,bfs和dfs的代码区别仅仅在于一个是栈顶出一个是队列出????迷惑行为