連結串列薈萃二：

• 迴文連結串列
• 列表解法

迴文連結串列

題目：迴文連結串列給定一個連結串列，判斷該連結串列是否是迴文連結串列，要求O(n)時間複雜度，O(1)空間複雜度。

Given a singly linked list, determine if it is a palindrome.

Example 1:

Input: 1->2
Output: false

Example 2:

Input: 1->2->2->1
Output: true

列表解法

O(n)時間複雜度，O(n)

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution:
    def isPalindrome(self, head):
        """
        :type head: ListNode
        :rtype: bool
        """
        result = []
        cur = head
        while(cur):
            result.append(cur.val)
            cur = cur.next
        return result == result[::-1]  
        #Note:result = [] result == result.reverse() --> False   
 

Ref：
1、迴文連結串列