题目描述

Python
blablabla

样例

blablabla

先取出链表的数据，然后两两交换

# Definition for singly-linked list.
# class ListNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.next = None
class Solution(object):
    def printListReversingly(self, head):
        """
        :type head: ListNode
        :rtype: List[int]
        """
        res = []
        while head is not None:
            res.append(head.val)
            head = head.next

        if res == [] : return  []
        n = len(res)
        l, r  = 0, n - 1
        while l < r:
            res[l], res[r] = res[r], res[l]
            l += 1
            r -= 1

        return res