def insert(self, pos=0, el=None):
"""
在指定位置插入新节点
pos 位置，从0开始
:return:
"""
if isinstance(pos, int):
if 0 > pos or pos > self.__size:
raise LinkListError('i is false %d' % (pos, ))
elif pos == 0:
self.push_front(el)
elif pos == self.__size:
self.push_back(el)
else:
count = 0
e = self.__head
while count != pos - 1:
e = e.next
count += 1
h = DLNode(el, n=e.next, p=e)
h.prev.next = h
h.next.prev = h
self.__size += 1
else:
raise LinkListError('param pos is not int type!!')
def isinList(self, el):
"""
el是否在链表中
:return:
"""
if isinstance(el, int):
if not self.__size:
#空链表，报错
raise LinkListError('linklist is empty')
p = self.__head
while p.elem != el and p:
p = p.next
return True if p.elem == el else False
else:
raise LinkListError('param el is not int type!!')
def delete(self, el):
"""
删除指的一个节点
:return:
"""
if not self.__size:
#空链表，报错
raise LinkListError('linklist is empty')
if self.__size == 1 and self.__head.elem == el:
self.__head = None
self.__tail = None
self.__size -= 1
elif self.__head.elem == el:
self.__head = self.__head.next
self.__head.prev = None
self.__size -= 1
else:
e = self.__head
p = None
while e:
if e.elem != el:
p = e
e = e.next
else:
if e == self.__tail:
self.__tail = p
self.__tail.next = None
else:
p.next = e.next
p.next.prev = p
self.__size -= 1
break
def back(self):
"""
返回最后一个节点
:return:
"""
if not self.__size:
#空链表，报错
raise LinkListError('linklist is empty')
return self.__tail
def front(self):
"""
返回第一个节点
:return:
"""
if not self.__size:
#空链表，报错
raise LinkListError('linklist is empty')
return self.__head
def get(self, i):
"""
访问链表i位置的节点
:return:
"""
if isinstance(i, int):
if not self.__size:
#空链表，报错
raise LinkListError('linklist is empty')
if 0 >= i or i > self.__size:
raise LinkListError('i is false %d' % (i, ))
n = 0
e = self.__head
while e.next and e.next is not self.__tail and n != i:
e = e.next
n += 1
return e.elem
else:
raise LinkListError('param i is not int type!!')
def elements(self):
"""
遍历链表所有节点
:return:
"""
if not self.__size:
#空链表，报错
raise LinkListError('linklist is empty')
p = self.__head
while p is not None:
yield p.elem
# print('el=%d, next=%d' % (p.elem, p.next),end='|')
p = p.next
def pop_front(self):
"""
删除链表头节点
:return:
"""
if not self.__size:
#空链表，报错
raise LinkListError('linklist is empty')
if self.__size == 1:
self.__head = None
self.__tail = None
else:
self.__head = self.__head.next
self.__head.prev = None
self.__size -= 1
def pop_back(self):
"""
删除链表尾节点
:return:
"""
if not self.__size:
#空链表，报错
raise LinkListError('linklist is empty')
if self.__size == 1:
self.__head = None
self.__tail = None
else:
self.__tail = self.__tail.prev
self.__tail.next = None
self.__size -= 1