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python單鏈表實(shí)現(xiàn)代碼實(shí)例

更新時(shí)間：2013年11月21日 14:25:13 作者：

這篇文章主要介紹了python單鏈表實(shí)現(xiàn)代碼,大家參考使用吧

鏈表的定義：
鏈表(linked list)是由一組被稱為結(jié)點(diǎn)的數(shù)據(jù)元素組成的數(shù)據(jù)結(jié)構(gòu)，每個(gè)結(jié)點(diǎn)都包含結(jié)點(diǎn)本身的信息和指向下一個(gè)結(jié)點(diǎn)的地址。由于每個(gè)結(jié)點(diǎn)都包含了可以鏈接起來的地址信息，所以用一個(gè)變量就能夠訪問整個(gè)結(jié)點(diǎn)序列。也就是說，結(jié)點(diǎn)包含兩部分信息：一部分用于存儲數(shù)據(jù)元素的值，稱為信息域；另一部分用于存儲下一個(gè)數(shù)據(jù)元素地址的指針，稱為指針域。鏈表中的第一個(gè)結(jié)點(diǎn)的地址存儲在一個(gè)單獨(dú)的結(jié)點(diǎn)中，稱為頭結(jié)點(diǎn)或首結(jié)點(diǎn)。鏈表中的最后一個(gè)結(jié)點(diǎn)沒有后繼元素，其指針域?yàn)榭铡！　?/P>

python單鏈表實(shí)現(xiàn)代碼：

復(fù)制代碼代碼如下:

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

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

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

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

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

self.head = q

        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

def delete(self,index):

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

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

self.head = q

        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

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
        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(jié)果：

5
6
4
40
5
6

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