# -*- coding:utf-8 -*-
class Node(object):
def __init__(self, value = None, next = None):
self.value = value
self.next = next
class Linklist(object):
def __init__(self, maxsize = None):
self.maxsize = maxsize
self.tailnode = None
self.length = 0
self.root = Node()
def __len__(self):
return self.length
def append(self, value):
if self.maxsize is not None and self.length > maxsize:
raise Exception("full")
node = Node(value)
if self.tailnode is None:
self.root.next = node
else:
self.tailnode.next = node
self.tailnode = node
self.length += 1
def appendleft(self, value):
node = Node(value)
if self.root.next is None:
self.root.next = node
self.tailnode = node
else:
oldhead = self.root.next
self.root.next = node
node.next = oldhead
self.length += 1
def iter_node(self):
curnode = self.root.next
while curnode is not self.tailnode:
yield curnode
curnode = curnode.next
yield curnode
def __iter__(self):
for node in self.iter_node():
yield node.value
def remove(self,value):
prevnode = self.root
for curnode in self.iter_node():
if curnode.value == value:
prevnode.next = curnode.next
if curnode is self.tailnode:
self.tailnode = prevnode
del curnode
self.length -= 1
return 1
else:
prevnode = curnode
return -1
def find(self, value): # 这个是返回列表，为了处理一个值返回多次的情况
l = []
index = 0
for node in self.iter_node():
if node.value == value:
l.append(index)
index += 1
if len(l) == 0:
return -1
else:
return l
def popleft(self):
if self.root.next is None:
raise Exception("链表为空")
headnode = self.root.next
self.root.next = headnode.next
value = headnode.value
del headnode
self.length -= 1
return value
def clear(self):
for node in self.iter_node():
del node
self.length = 0
self.root.next = None
def test_linklist():
ll = Linklist()
ll.append(1)
ll.append(2)
ll.append(3)
ll.append(100)
assert len(ll) == 4
l = ll.find(100)
l = ll.find(100)
assert l[0] == 3
assert ll.find(231) == -1
ll.remove(100)
assert len(ll) == 3
assert ll.find(100) == -1
assert list(ll) == [1, 2, 3]
ll.appendleft(0)
assert list(ll) == [0, 1, 2, 3]
assert len(ll) == 4
headnode = ll.popleft()
assert headnode == 0
assert len(ll) == 3
assert list(ll) == [1, 2, 3]
ll.clear()
len(ll) == 0
test_linklist()
