定义一个函数,输入一个链表的头节点,反转该链表并输出反转后链表的头节点。
示例1: 输入: 1->2->3->4->5->NULL 输出: 5->4->3->2->1->NULL 示例2: 输入:head = [1,2,3,4,5] 输出:[5,4,3,2,1] 来源:力扣(LeetCode) 链接:https://leetcode-cn.com/problems/reverse-linked-list/ https://leetcode-cn.com/problems/fan-zhuan-lian-biao-lcof/
#python3 # Definition for singly-linked list. # class ListNode: # def __init__(self, x): # self.val = x # self.next = None class Solution: def reverseList(self, head: ListNode) -> ListNode: q=None p=head while p: n=p.next p.next=q q=p p=n return q