class Node:
def __init__(self, value):
self.value = value
self.next = None
def __str__(self):
return "Node({})".format(self.value)
__repr__ = __str__
class Queue:
def __init__(self):
self.head=None
self.tail=None
def __str__(self):
temp=self.head
out=[]
while temp:
out.append(str(temp.value))
temp=temp.next
out=' '.join(out)
return ('Head:{}\nTail:{}\nQueue:{}'.format(self.head,self.tail,out))
__repr__=__str__
def isEmpty(self):
#write your code here
return (self.head == None) and (self.tail == None)
def __len__(self):
#write your code here
current = self.head
len = 0
while current:
len += 1
current = self.head.next
if self.head.next == self.tail:
break
return len
def enqueue(self, value):
#write your code here
node = Node(value)
if self.isEmpty():
self.head = node
self.tail = node
else:
self.tail.next = node
self.tail = node
def dequeue(self):
#write your code here
if self.isEmpty():
return 'Queue is empty'
else:
popped = self.head.value
self.head = self.head.next
return popped
def front(self):
if self.head != None:
return self.head.value
q = Queue()
def reversequeue(q):
if q.isEmpty() == False:
data = q.front()
q.dequeue()
reversequeue(q)
q.enqueue(data)
def QueuePalindrome(word):
q = Queue()
for i in word:
q.enqueue(i)
p = reversequeue(q)
return p
函数reversequeue返回“Nonetype”对象没有属性值。我不知道该怎么办。你知道吗
当我测试q.front()时。它返回正确答案。我试图抓住错误,说如果自首==无则跳过。你知道吗
在这种情况下我该怎么办?你知道吗
请帮忙。非常感谢!你知道吗
函数
reversequeue(q)
没有return
语句因此它默认返回
None
。只需为基本情况和递归情况添加一个返回,并更新q
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