python链表实现多项式_Python链表实现

import logging

logging.basicConfig(

level=logging.DEBUG,

format='%(asctime)s-%(name)s-%(levelname)s-%(message)s')

logger = logging.getLogger(__name__)

class Node():

def __init__(self, data=None):

self._data = data

self._next = None

@property

def data(self):

return self._data

@data.setter

def data(self, value):

self._data = value

@property

def next(self):

return self._next

@next.setter

def next(self, value):

self._next = value

def __str__(self):

return 'Node:' % (self._data, self._next)

class LinkedList():

def __init__(self): # head.data=length of the linkedlist

self._head = Node(0)

self._tail = self._head

def __len__(self):

return self._head.data

def __bool__(self):

return bool(self._head.data)

def __str__(self):

linkedlist = self._data2list()

return 'linkedlist:%s' % str(linkedlist) # 将str的打印方式委托给了list的__str__

def __contains__(self, value):

linkedlist = self._data2list()

return value in linkedlist

def generate_node(self):

node = self._head.next

while node != None:

yield node

node = node.next

def _data2list(self):

if self._head.data == 0:

return []

else:

return [x.data for x in self.generate_node()]

def add(self, value): # 尾部增加

node = Node(value)

self._tail.next = node

self._tail = node

self._head.data += 1

def pop(self, value):

assert self.__contains__(value) == True, 'there is no value%s' % value

if value == self._head.next.data:

self._head.next = self._head.next.next

else:

nodes = list(self.generate_node()) # list代码清晰，但是空间会占用大些

for index in range(self.__len__):

cur_node = nodes[index]

if cur_node.data == value:

pre_node = nodes[index-1]

if index == self._length-1:

next_node = None

else:

next_node = nodes[index+1]

logger.info('the data:%shas been deleted, and the pre node is%s' %

(cur_node.data, pre_node.data))

pre_node.next = next_node

def superpop(self, node):

assert node.next != None, 'must not be the tail'

node.data = node.next.data

node.next = node.next.next

def main():

x = LinkedList()

for i in range(5):

x.add(i)

print('length% 2d, the data is%s' % (len(x), x))

x.pop(0)

print(x)

if __name__ == '__main__':

main()