206. 反转链表 - 力扣（LeetCode）

图示

代码

# encoding = utf-8
# 开发者：Alen
# 开发时间： 16:06 
# "Stay hungry，stay foolish."

# Definition for singly-linked list.
# class ListNode(object):
#     def __init__(self, val=0, next=None):
#         self.val = val
#         self.next = next
class Solution(object):
    def reverseList(self, head):
        """
        :type head: Optional[ListNode]
        :rtype: Optional[ListNode]
        """
        def reverseList(node):
            prev = None
            cur = head
            while cur:
                next_temp = cur.next # 保存下一个节点
                cur.next = prev # 指针反向
                prev = cur # prev前移
                cur = next_temp # cur前移
            return prev
        return reverseList(head)

结果

解题步骤：www.bilibili.com