Python二重リンクリスト実装サンプルコード

示意图：

python双向链表实现代码：

复制代码 代码如下:

#!/usr/bin/python
# -*- coding: utf-8 -*-

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

class LinkList(object):
    def __init__(self):
        self.head = 0

    def __getitem__(self, key):

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

        elif key <0 or key > self.getlength():
            print 'the given key is error'
            return

        else:
            return self.getitem(key)

 

    def __setitem__(self, key, value):

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

        elif key <0 or key > self.getlength():
            print 'the given key is error'
            return

        else:
            self.delete(key)
            return self.insert(key)

    def initlist(self,data):

        self.head = Node(data[0])

        p = self.head

        for i in data[1:]:
            node = Node(i)
            p.next = node
            node.prev  = p
            p = p.next

    def getlength(self):

        p =  self.head
        length = 0
        while p!=0:
            length+=1
            p = p.next

        return 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
            q.prev = p

    def getitem(self,index):

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

while p.next!=0 and j
p = p.next
j+=1

if j ==index:
return p.data

その他:

print 'ターゲットは存在しません!'

def insert(self,index,item):

if self.is_empty()、indexself.getlength():
print 'リンクリストが空です。'
return

ifindex ==0:
q = Node(item,self.head)

self.head = q

p = self.head
post = self.head
j = 0
while p.next!=0 and j post = p
p = p。次
j+=1

ifindex ==j:
q = Node(item,p)
post.next = q
q.prev = post
q.next = p
p.prev =q

def delete(self,index):

if self.is_empty()、indexself.getlength():
print 'リンクリストが空です。'
return

ifindex ==0:
q = Node(item,self.head)

self.head = q

p = self.head
post = self.head
j = 0
while p.next!=0 and j post = p
p = p。次
j+=1

ifindex ==j:
post.next = p.next
p.next.prev = post

defindex(self,value):

if self.is_empty():
print 'リンクリストが空です。'
return

p = self.head
i = 0
ただし p.next!=0 ではなく p.data ==value:
p = p.next
i+=1

if p.data == value:
return i
else:
return -1

l = LinkList()
l.initlist([1,2,3,4,5])
print l.getitem(4)
l.append(6)
print l.getitem(5)

l.insert(4,40)
print l.getitem(3)
print l.getitem(4)
print l.getitem(5)

l.delete(5)
print l.getitem(5)

l.index(5)

結果は；

5
6
4
40
5
6

と単一のテーブルの結果も同様です。