题解 | #链表中倒数最后k个结点#

# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None
#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param pHead ListNode类 
# @param k int整型 
# @return ListNode类
#
class Solution:
    def FindKthToTail(self , pHead: ListNode, k: int) -> ListNode:
        n=0
        cur=pHead
        while cur:
            n=n+1
            cur=cur.next
        cur=pHead
        if n-k<0:
           return None
        else:
            for i in range(n-k):
               cur=cur.next
            return cur