思路1:遍历一次链表,用一个数组存储链表节点值,然后用双指针法判断数组是否是回文的。需要额外O(n)的空间。 C++ classSolution{public:boolisPalindrome(ListNode* head){if(!head || !head->next)returntrue; vector<int> vec;while(head) { vec.push_back(head->val); head = head->next; }for(inti ...
先看看list有多长。然后把前半截的node values逐个push到一个stack里。然后从后半截开始逐个比较node value和stack[-1]。注意list长度为奇偶的两种情况。奇数时,先pop掉中间一个。 1classSolution(object):2defisPalindrome(self, head):3"""4:type head: ListNode5:rtype: bool6"""7ifnotheadornothead.next...
Can you solve this real interview question? Palindrome Linked List - Given the head of a singly linked list, return true if it is a palindrome or false otherwise. Example 1: [https://assets.leetcode.com/uploads/2021/03/03/pal1linked-list.jpg] Inpu
思路 两个指针都从头出发,快指针每次两步,慢指针每次一步,这样快指针的下一个或下下个为空时,慢指针就在链表正中间那个节点了(如果链表有偶数个节点则在靠近头那侧的)。然后我们从慢指针的下一个开始,把后面的链表都反转(Reverse Linked List),然后我们再从头和从尾同时向中间前进,就可以判断该链表是不是回文...
LeetCode: 234. Palindrome Linked List 题目描述 Given a singly linked list, determine if it is a palindrome. Example 1: Input: 1->2 Output: false 1. 2. Example 2: Input: 1->2->2->1 Output: true 1. 2. Follow up: Could you do it in O(n) time and ...
Leetcode 234 Palindrome Linked List 复杂度为时间O(n) 和空间(1)解法,1.问题描写叙述给定一个单链表,推断其内容是不是回文类型。比如1–>2–>3–>2–>1。时间和空间复杂都尽量低。2.方法与思路1)比較朴素的算法。因为给定的数据结构是单链表,要訪问链表的尾部元素,
My code: /** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */publicclassSolution{publicbooleanisPalindrome(ListNodehead){if(head==null||head.next==null){returntrue;}ArrayList<Integer>al=newArrayList<Int...
234. Palindrome Linked List 请判断一个链表是否为回文链表。 示例1: 输入:1->2输出:false 示例2: 输入:1->2->2->1输出:true 进阶: 你能否用 O(n) 时间复杂度和 O(1) 空间复杂度解决此题? 来源:力扣(LeetCode) 链接:https://leetcode-cn.com/problems/palindrome-linked-list著作权归领扣网络所有...
Leetcode-Easy 234. Palindrome Linked List 描述: 判断一个单链表是否左右对称 代码语言: 代码运行次数: # Definitionforsingly-linked list.#classListNode:# def__init__(self,x):# self.val=x # self.next=NoneclassSolution(object):defisPalindrome(self,head):""":type head:ListNode:rtype:bool"""...
LeetCode problem solving notes. Determine whether a linked list is a palindrome linked list. First convert the linked list into an array, and then judge whether the array is a palindrome array.