python链表

class LNode(object):
    # 结点初始化函数, p 即模拟所存放的下一个结点的地址
    # 为了方便传参, 设置 p 的默认值为 0
    def __init__(self, data, p=0):
        self.data = data
        self.next = p


class LinkList(object):
    def __init__(self):
        self.head = None

    # 链表初始化函数, 方法类似于尾插
    def initList(self, data):
        # 创建头结点
        self.head = LNode(data[0])
        p = self.head
        # 逐个为 data 内的数据创建结点, 建立链表
        for i in data[1:]:
            node = LNode(i)
            p.next = node
            p = p.next

    # 链表判空
    def isEmpty(self):
        if self.head.next == 0:
            print("Empty List!")
            return 1
        else:
            return 0

    # 取链表长度
    def getLength(self):
        if self.isEmpty():
            exit(0)

        p = self.head
        len = 0
        while p:
            len += 1
            p = p.next
        return len

    # 遍历链表
    def traveList(self):
        if self.isEmpty():
            exit(0)
        print('\rlink list traving result: ', )
        p = self.head
        while p:
            print(p.data, )
            p = p.next

    # 链表插入数据函数
    def insertElem(self, key, index):
        if self.isEmpty():
            exit(0)
        if index < 0 or index > self.getLength() - 1:
            print("\rKey Error! Program Exit.")
            exit(0)

        p = self.head
        i = 0
        while i <= index:
            pre = p
            p = p.next
            i += 1

        # 遍历找到索引值为 index 的结点后, 在其后面插入结点
        node = LNode(key)
        pre.next = node
        node.next = p

    # 链表删除数据函数
    def deleteElem(self, index):
        if self.isEmpty():
            exit(0)
        if index < 0 or index > self.getLength() - 1:
            print("\rValue Error! Program Exit.")
            exit(0)

        i = 0
        p = self.head
        # 遍历找到索引值为 index 的结点
        while p.next:
            pre = p
            p = p.next
            i += 1
            if i == index:
                pre.next = p.next
                p = None
                return 1

        # p的下一个结点为空说明到了最后一个结点, 删除之即可
        pre.next = None


# 初始化链表与数据
data = [1, 2, 3, 4, 5]
l = LinkList()
l.initList(data)
l.traveList()

# 插入结点到索引值为3之后, 值为666
l.insertElem(666, 3)
l.traveList()

# 删除索引值为4的结点
l.deleteElem(4)
l.traveList()