题目:
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
进阶:
你可以迭代或递归地反转链表。你能否用两种方法解决这道题?
来源:https://leetcode-cn.com/problems/reverse-linked-list
打卡:
# Definition for singly-linked list.
# class ListNode:
# def __init__(self, val=0, next=None):
# self.val = val
# self.next = next
class Solution:
def reverseList(self, head: ListNode) -> ListNode:
p1=head
p2=None
while p1:
tmp=ListNode(p1.val)
tmp.next=p2
p2=tmp
p1=p1.next
return p2