剑指 Offer 22. 链表中倒数第k个节点
# Definition for singly-linked list.
# class ListNode:
# def __init__(self, x):
# self.val = x
# self.next = None
class Solution:
def getKthFromEnd(self, head: ListNode, k: int) -> ListNode:
if head is None:
return head
first, last = head, head
while k > 0:
if last is None:
return None
last = last.next
k -= 1
while last:
first = first.next
last = last.next
return first
