Python单链表-删除元素
出于某种原因,我的remove_element方法不会删除包含元素的所有节点。为什么?Python单链表-删除元素,python,data-structures,Python,Data Structures,出于某种原因,我的remove_element方法不会删除包含元素的所有节点。为什么? class Node: def __init__(self, element): self.element = element self.next = None class SLL: def __init__(self): self.head = None # add a node to front def add_front
class Node:
def __init__(self, element):
self.element = element
self.next = None
class SLL:
def __init__(self):
self.head = None
# add a node to front
def add_front(self, element):
new_node = Node(element)
if self.head == None:
self.head = new_node
else:
new_node.next = self.head
self.head = new_node
# removes from the head
def remove(self):
if self.head == None:
print "Error: the list is empty."
else:
self.head = self.head.next
# removes all nodes which hold a given element
def remove_element(self, element):
previous = None
cursor = self.head
while cursor != None:
if cursor.element == element:
if cursor == self.head:
self.remove()
else:
previous.next = cursor.next
previous = cursor
cursor = cursor.next
# traverses the list and prints out its elements
def print_list(self):
cursor = self.head
while (cursor != None):
print(cursor.element)
cursor = cursor.next
# Main
SLL = SLL()
SLL.add_front(21)
SLL.add_front(21)
SLL.add_front(1)
SLL.add_front(1)
SLL.add_front(1)
SLL.add_front(2)
SLL.add_front(3)
SLL.add_front(5)
SLL.add_front(8)
SLL.add_front(13)
SLL.add_front(21)
SLL.print_list()
print
SLL.remove_element(1)
SLL.print_list()
print
输出:
bash-3.2$ python SLL.py
21
13
8
5
3
2
1
1
1
21
21
21
13
8
5
3
2
1 <--- What is this guy doing here?
21
21
bash-3.2$python SLL.py
21
13
8.
5.
3.
2.
1.
1.
1.
21
21
21
13
8.
5.
3.
2.
1删除元素时,无需移动上一个变量引用:
while cursor != None:
if cursor.element == element:
if cursor == self.head:
self.remove()
else:
previous.next = cursor.next
else:
previous = cursor
cursor = cursor.next
否则,每次删除元素时,都会通过重新指定previous
和cursor
变量跳过下一个元素。为什么要在Python中实现链表?除非是家庭作业,否则没有理由这么做。此外,PEP8建议在与None
进行比较时使用is
和is
。只需修改数据结构并自学python@ThiefMaster谢谢将必须阅读整个风格建议文档。作为一项额外任务,一旦一切正常,添加一些类似于\uuuuu iter\uuuuu
和\uuuu包含
的内容将是一个不错的主意,这样您就可以使用常见的运算符/语句(如果条形图中有foo
,条形图中有foo
,等等)在您的结构上。光标
仍然需要更改。无限循环:)但是谢谢,我明白了-我只需要调整cursor@interjay,是的,还有缩进问题。谢谢你指出错误!