LeetCode 206 反转链表
反转一个单链表。
示例:
输入: 1->2->3->4->5->NULL 输出: 5->4->3->2->1->NULL
# Definition for singly-linked list. # class ListNode(object): # def __init__(self, x): # self.val = x # self.next = None class Solution(object): def reverseList(self, head): """ :type head: ListNode :rtype: ListNode """ if not head or not head.next: return head l = head r = head.next head.next = None while(r): t = r.next r.next = l l = r r = t return l