從尾到頭打印鏈表

class Solution:
    def reversePrint(self, head: ListNode) -> List[int]:
        if not head:
            return []
        root = self.reverseLink(head)
        cur = root
        res = [] 
        while cur:
            res.append(cur.val)
            cur = cur.next 
        self.reverseLink(root)
        return res 
    def reverseLink(self, head: ListNode) :
        dy = None 
        cur, tmp = head, head 
        while cur:
            tmp = cur.next 
            cur.next = dy
            dy, cur = cur, tmp
        return dy

https://leetcode-cn.com/problems/cong-wei-dao-tou-da-yin-lian-biao-lcof/