题目描述
输入一个链表，输出该链表中倒数第k个结点。
Solution：
定义两个指针，指针A先移动k-1个节点，然后两个指针A,B再一块移动，当指针A移动到尾结点时，则指针B正好移动在倒数第K个结点。
CODE:
class Solution:
def FindKthToTail(self,head,k):
if not head:
return None
else:
pointer1,pointer2 = head,head
while k > 1:
if pointer1.next != None:
pointer1 = pointer1.next
k -= 1
else:
return None
while pointer1.next != None:
pointer1 = pointer1.next
pointer2 = pointer2.next
return pointer2