Python单链表的基本操作

“””

初始化链表

“””

import time

class Node:

    def __init__(self,value):

        self.value = value

        self.next = None

class SingleLinkList:

    def __init__(self):

        self.head = None

    def is_empty(self):

        “””判断是否为空”””

        return self.head == None

    def travel(self):

        “””遍历链表”””

        cur = self.head

        while cur is not None:

            print(cur.value,end=” “)

            cur = cur.next

    def append(self,item):

        “””在末尾添加节点”””

        node = Node(item)

        # 如果是空链表

        if self.is_empty():

            self.head = node

            return

        # 当不为空的时候

        cur = self.head

        while cur.next:

            cur = cur.next

        cur.next = node

        # node.next = None

    def insert(self,index,item):

        “””插入中间节点”””

        if (self.head is None) and (self.head.next is None):

            return

        cur = self.head

        while cur is not None and index > 1:

            index = index – 1

            cur = cur.next

        node = Node(item)

        node.next = cur.next

        cur.next = node

    def add(self,item):

        “””在头部添加节点”””

        node = Node(item)

        node.next = self.head

        self.head = node

    def length(self):

        “””获取链表的长度”””

        cur = self.head

        count = 0

        while cur is not None:

            count += 1

            cur = cur.next

        return count

    def search(self,item):

        # 查看item在链表中是否存在

        cur = self.head

        while cur != None:

            if cur.value == item:

                return True

            else:

                cur = cur.next

        return False

    def pop_last(self):

        “””弹出链表的最后一个元素”””

        if self.head is None:

            return

        cur = self.head

        if cur.next is None:

            self.head = None

            return

        while cur.next.next is not None:

            cur = cur.next

        cur.next = None

    def pop_head(self):

        “””把链表的第一个元素弹出”””

        if self.head is None:

            return

        self.head = self.head.next

    def cycle(self):

        “””循环输出链表”””

        cur = self.head

        if cur.next == None:

            cur.next = self.head

        while cur.next != None:

            self.travel()

            time.sleep(3)

if __name__ == ‘__main__‘:

    s = SingleLinkList()

    s.append(100)

    s.append(300)

    s.append(600)

    s.add(500)

    s.add(150)

    head = Node(30)

    head.next = Node(40)

    head.next.next = Node(50)

    s.pop_head()

    s.pop_last()

    s.cycle()

    s.travel()

Python单链表的基本操作

原文地址：https://www.cnblogs.com/mengjie1016/p/13378316.html