LeetCode206 反转链表

思路

代码

#

# @lc app=leetcode.cn id=206 lang=python3

#

# [206] 反转链表

#

# https://leetcode-cn.com/problems/reverse-linked-list/description/

#

# algorithms

# Easy (61.53%)

# Likes:    624

# Dislikes: 0

# Total Accepted:    112.8K

# Total Submissions: 172.9K

# Testcase Example:  '[1,2,3,4,5]'

#

# 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？

#

#

# @lc code=start

# 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:

        cur, prev = head, None

        while cur:

            cur.next, prev, cur = prev, cur, cur.next

        return prev

# @lc code=end