题解 | #反转链表#

# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None
#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
#
# @param head ListNode类
# @return ListNode类
#
class Solution:
    def ReverseList(self, head: ListNode) -> ListNode:
        # write code here
        if not head:
            return head
        rehead = head.next
        renode = head
        head.next = None
        while rehead:
            newRehead = rehead.next
            rehead.next = renode
            renode = rehead
            rehead = newRehead

        
        return renode