Total Accepted: 40445 Total Submissions: 148124 Difficulty: Easy Given a singly linked list, determine if it is a palindrome. Follow up: Could you do it in O(n) time and O(1) space? 分析: 临时没想到空间为O(1)的方法,直白的模拟思想,遍历一遍记录各节点的元素 再对数组前尾比較就可以. /** * Definiti…

#-*- coding: UTF-8 -*-class Solution(object):    def isPalindrome(self, head):        """        :type head: ListNode        :rtype: bool        """        if head==None or head.next==None:return True        resList=[]       …

234. Palindrome Linked List 1. 使用快慢指针找中点的原理是fast和slow两个指针,每次快指针走两步,慢指针走一步,等快指针走完时,慢指针的位置就是中点.如果是偶数个数,正好是一半一半,如果是奇数个数,慢指针正好在中间位置,判断回文的时候不需要比较该位置数据. 注意好好理解快慢指针的算法原理及应用. 2. 每次慢指针走一步,都把值存入栈中,等到达中点时,链表的前半段都存入栈中了,由于栈的后进先出的性质,就可以和后半段链表按照回文对应的顺序比较. solution…

Question 234. Palindrome Linked List Solution 题目大意:给一个链表,判断是该链表中的元素组成的串是否回文 思路:遍历链表添加到一个list中,再遍历list的一半判断对称元素是否相等,注意一点list中的元素是Integer在做比较的时候要用equals,因为int在[-128,127)之间在内存中是存储在运行时常量池中,超出这个范围作为对象存储在堆中,==比较的是字面值和对象地址 Java实现: public boolean isPalindrom…

234. Palindrome Linked List[easy] Given a singly linked list, determine if it is a palindrome. Follow up:Could you do it in O(n) time and O(1) space? 解法一: /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * Lis…

Palindrome Linked List Given a singly linked list, determine if it is a palindrome. Follow up:Could you do it in O(n) time and O(1) space? 解法一: 一次遍历,装入vector,然后再一次遍历判断回文. 时间复杂度O(n),空间复杂度O(n) /** * Definition for singly-linked list. * struct ListNode…

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 Follow up:Could you do it in O(n) time and O(1) space? 这道题让我们判断一个链表是否为回文链表,LeetCode 中关于回文串的题共有六道,除了这道,其…

Given a singly linked list, determine if it is a palindrome. Follow up:Could you do it in O(n) time and O(1) space? 题目标签:Linked List 题目给了我们一个 linked list,让我们判断它是不是回文. 这里可以利用 #206 Reverse Linked List 把右边一半的链表 倒转,然后从左右两头开始比较链表是否是回文. 这样的话,首先要找到链表的中间点,然后…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 日期 题目地址:https://leetcode.com/problems/palindrome-linked-list/#/description 题目描述 Given a singly linked list, determine if it is a palindrome. Follow up: Could you do it in O(n)…

Given a singly linked list, determine if it is a palindrome. Follow up:Could you do it in O(n) time and O(1) space? 思想:转置后半段链表节点,然后比较前半段和后半段节点的值是否相等. 代码如下: /** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next;…