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 , k ):
        # write code here
        node = pHead
        n = 0
        while(node):
            node = node.next
            n+=1
        result = None
        if n < k:
            return result
        elif n == k:
            return pHead
        else:
            m = n-k
            for i in range(m):
                pHead = pHead.next
            return pHead