单向链表实现及倒序

单向链表

单向链表也称链表，python没有原生结构与之对应，参考前辈博客做了一版简化实现如下
附前辈博客地址：https://www.cnblogs.com/yupeng/p/3413763.html

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


class LinkList(object):
	# 支持头节点创建及列表创建
    def __init__(self, node=0, data=[]):
        if not data:
            self.head = node
        else:
            self.head = Node(data[0])
            p = self.head
            for i in data[1:]:
                node = Node(i)
                p.next = node
                p = p.next

    def ptlist(self):
        p = self.head
        while p.next != 0:
            print(p.data, end=' ')
            p = p.next
        print(p.data)
   
l = LinkList(data=[1, 2, 3, 4, 5])
l.ptlist()  # output：1 2 3 4 5

单向链表倒序

单向链表的反序使用递归结构即可实现，同时由于单向链表结构特殊，需要将链表头作为递归项

def link_reverse(p):
    if p.next == 0:
        return p
    new_head = link_reverse(p.next)
    new_tail = new_head
    while new_tail.next != 0:
        new_tail = new_tail.next
    new_tail.next = p
    p.next = 0
    return new_head

p = link_reverse(l.head)
ll = LinkList(p)
ll.ptlist() # output: 5 4 3 2 1