leetcode 234.回文链表

生信研究猿2026-04-04 9:05

暴力解法：

python 复制代码

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, val=0, next=None):
#         self.val = val
#         self.next = next
class Solution:
    def isPalindrome(self, head: Optional[ListNode]) -> bool:

        if head.next==None:
            return True

        list1 = []
        A = head
        while(A!=None):
            list1.append(A.val)
            A = A.next
        
        
        tou = 0
        wei = len(list1)-1
        if len(list1)%2==0:
            while(tou!=(wei-1)):
                if (list1[tou] != list1[wei]):
                    return False
                tou += 1
                wei -= 1
            if (list1[tou]==list1[wei]):
                return True
            else:
                return False    
        else:
            while(tou!=(wei-2)):
                if (list1[tou] != list1[wei]):
                    return False
                tou += 1
                wei -= 1
            if (list1[tou]==list1[wei]):
                return True
            else:
                return False

官方代码（完全没想到 vals == vals[::-1]）：

python 复制代码

class Solution:
    def isPalindrome(self, head: ListNode) -> bool:
        vals = []
        current_node = head
        while current_node is not None:
            vals.append(current_node.val)
            current_node = current_node.next
        return vals == vals[::-1]

作者：力扣官方题解
链接：https://leetcode.cn/problems/palindrome-linked-list/solutions/457059/hui-wen-lian-biao-by-leetcode-solution/
来源：力扣（LeetCode）
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