用python实现链表操作

class Node(object):
def __init__(self,data,p=0):
self.data = data
self.next = p
class LinkList(object):
def __init__(self):
self.head = 0

def initlist(self):

print("input numbers here.'!' to quit")

data=input()
if data is not '-1':
self.head=Node(int(data))
p=self.head
while data != '-1':
data=input()
if data == '-1':
break
else:
p.next=Node(int(data))
p=p.next

print("输入结束！")
#print("输入结束,当前序列为:")
#p=self.head
#while p!=0:
#    print(p.data)
#    p=p.next

def getlength(self):
p = self.head
length = 0
while p!=0:
length+=1
p = p.next

#return length
print("当前链表的长度为%d="%length)

def is_empty(self):

if self.getlength() ==0:
return True
else:
return False

def clear(self):

self.head = 0

def append(self,item):

q = Node(item)
if self.head ==0:
self.head = q
else:
p = self.head
while p.next!=0:
p = p.next
p.next = q
print("在链表尾部插入数据后，链表为:")
p=self.head
while p!=0:
print(p.data)
p=p.next

def getitem(self,index):

if self.is_empty():
print ('Linklist is empty.')
return
j = 0
p = self.head

while p.next!=0 and j <index:
p = p.next
j+=1

if j ==index:
#return p.data
print("在链表的%d位置上的数值是"%(p.data))

else:

print ('target is not exist!')

def insert(self,index,item):

if self.is_empty() or index<0 or index >self.getlength():
print ('Linklist is empty.')
return
p=self.head
if index ==0:
q = Node(item)
q.next=self.head
self.head=q
else:
p = self.head
post  = self.head
j = 0
while p.next!=0 and j<index:
post = p
p = p.next
j+=1

if index ==j:
q = Node(item,p)
post.next = q
q.next = p
p=self.head
print("插入某个值后的链表")
while p!=0:
print(p.data)
p=p.next

def delete(self,index):

if self.is_empty() or index<0 or index >self.getlength():
print ('Linklist is empty.')
return
p=self.head
if index ==0:
q = self.head

self.head = q.next
p=self.head
else:
p = self.head
post  = self.head
j = 0
while p.next!=0 and j<index:
post = p
p = p.next
j+=1

if index ==j:
post.next = p.next
print("删除某个节点后的链表:")
p=self.head
while p!=0:
print(p.data)
p=p.next
def index(self,value):

if self.is_empty():
print ('Linklist is empty.')
return

p = self.head
i = 0
while p.next!=0 and not p.data ==value:
p = p.next
i+=1

if p.data == value:
#return i
print("要找的值在链表中的第%d位,"%(i+1))
else:
#return -1
print("没有此值!")

def rever(self):
self.initlist()

p=self.head
nex=self.head.next
pre=Node(0)
while self.head.next!=0:
nex=self.head.next
self.head.next=pre
pre=self.head
self.head=nex
self.head.next=pre
pre=self.head1

print("逆序输出节点:")
#此处的0是链表结尾处代表结束的，而pre链表的整个序列是2,1,0-->这个0代表整数0
while pre.next!=0:
print(pre.data)
pre=pre.next

if __name__=="__main__":
l = LinkList()
l.initlist()
#l.rever()
#l.getlength()
#l.getitem(0)
#l.delete(0)
#l.insert(0,1)
#l.index(2)
#l.getitem(0)
l.append(1)