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:
        # write code here
        fast = pHead
        slow = pHead
        for i in range(k):
            if fast is None:
			  # 很离谱的是这个return None报红，所以我一直以为我的代码有问题
                return None
            else:
                fast = fast.next
        while fast:
            fast = fast.next
            slow = slow.next
        return slow