Python 3 递归链表节点插入

Question

我正在尝试创建一个递归函数以在特定位置插入链表以解决 hackerrank challenge 问题，作为 python self 教育的一部分。但是，(根据 hackerrank)这似乎是不正确的。有人可以帮助解释我可能哪里出错了吗？

"""
 Insert Node at a specific position in a linked list
 head input could be None as well for empty list
 Node is defined as

 class Node(object):

   def __init__(self, data=None, next_node=None):
       self.data = data
       self.next = next_node

 return back the head of the linked list in the below method. 
"""

def InsertNth(head, data, position):

    # if we've found our position, then insert Node with pointer to next/None
    if head == None or position == 0 :
        return Node(data, head)

    # if we're at the next to last position, then update it's pointer to our new Node
    elif position == 1  :
        head.next = Node(data, head.next)

    # otherwise, step position down, and perform recursion
    else :
        InsertNth(head.next, data, position-1)

我已经在评论中尝试解释我所理解的逻辑，所以如果有任何不清楚的地方，请告诉我。

Answer 1

发布了一个被 hackerrank 接受的解决方案:

def InsertNth(head, data, position):
    # if we have found our position, then create a new Node 
    if head == None or position == 0 :
        return Node(data, head)
    else :
        next_node = head
        while position > 1 :
            next_node = next_node.next
            position -= 1

        next_node.next = Node(data, next_node.next)

    return head