Leetcode 206 Reverse Linked List

Reverse a singly linked list.

Example:

Input: 1->2->3->4->5->NULL
Output: 5->4->3->2->1->NULL

# 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:
        if head == None:
            return None
        # L  M  R
        # M -> L
        L = None
        M = None
        R = head
        while R.next != None:
            L = M
            M = R
            R = R.next
            M.next = L
        R.next = M
        return R

 

来源：https://blog.csdn.net/huyun9666/article/details/100941222