Python单链表的基本操作

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()

本文地址：https://blog.csdn.net/weixin_46120601/article/details/107553124