Reverse a linked list from position m to n. Do it in-place and in one-pass. For example:Given 1->2->3->4->5->NULL, m = 2 and n = 4, return 1->4->3->2->5->NULL. Note:Given m, n satisfy the following condition:1 ≤ m ≤ n ≤ lengt…

Reverse a linked list from position m to n. Do it in-place and in one-pass. For example:Given1->2->3->4->5->NULL, m = 2 and n = 4, return1->4->3->2->5->NULL. Note:  Given m, n satisfy the following condition:1 ≤ m ≤ n ≤ lengt…

Reverse a linked list from position m to n. Do it in-place and in one-pass. For example: Given 1->2->3->4->5->NULL, m = 2 and n = 4, return 1->4->3->2->5->NULL. Note: Given m, n satisfy the following condition: 1 ≤ m ≤ n ≤ le…

题意:将指定的一段位置[m,n]的链表反置,返回链表头. 思路:主要麻烦在链表头,如果要从链表头就开始,比较特殊. 目前用DFS实现,先找到m-1的位置,再找到n+1的位置,中间这段就是否要反置的,交给DFS解决,用个计数器来统计已经反置的个数即可. /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(N…

题意:给一个单链表,每k个节点就将这k个节点反置,若节点数不是k的倍数,则后面不够k个的这一小段链表不必反置. 思路:递归法.每次递归就将k个节点反置,将k个之后的链表头递归下去解决.利用原来的函数接口即可,不用重新定义. /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; *…

Reverse a singly linked list. click to show more hints. Hint: A linked list can be reversed either iteratively or recursively. Could you implement both? 之前做到Reverse Linked List II 倒置链表之二的时候我还纳闷怎么只有二没有一呢,原来真是忘了啊,现在才加上,这道题跟之前那道比起来简单不少,题目为了增加些许难度,让我们分别用…

Reverse a linked list from position m to n. Do it in one-pass. Note: 1 ≤ m ≤ n ≤ length of list. Example: Input: 1->2->3->4->5->NULL, m = 2, n = 4 Output: 1->4->3->2->5->NULL 很奇怪为何没有倒置链表之一,就来了这个倒置链表之二,不过猜也能猜得到之一就是单纯的倒置整个链表,而这…

Reverse a linked list from position m to n. Do it in-place and in one-pass. For example:Given 1->2->3->4->5->NULL, m = 2 and n = 4, return 1->4->3->2->5->NULL. Note:Given m, n satisfy the following condition:1 ≤ m ≤ n ≤ lengt…

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? 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,其他的五道为Palindrome Number 验证回文数字,Validate Palindrome 验证回文字符串,Palindrome Partitioning 拆分回文…

题目:Reverse Linked List II 题意:Reverse a linked list from position m to n. Do it in-place and in one-pass. 下面这段代码,有两个地方,一个是4.5行的dummy节点设置:另一个是11-14行,局部可视化到全局. ListNode *reverseBetween(ListNode *head, int m, int n) { if(m == n) return head; n -= m; List…

Given a linked list, return the node where the cycle begins. If there is no cycle, return null. Follow up:Can you solve it without using extra space? 141. Linked List Cycle 的拓展,这题要返回环开始的节点,如果没有环返回null. 解法:双指针,还是用快慢两个指针,相遇时记下节点.参考:willduan的博客 Java: pu…

题意: 将单恋表反转. 思路: 两种方法:迭代和递归. 递归 /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */ class Solution { public: ListNode* give_me_your_son( ListNode* far, ListNode* s…

Reverse a singly linked list. 题目标签:Linked List 题目给了我们一个链表,要求我们倒转链表. 利用递归,新设一个newHead = null,每一轮 把下一个 node 存入 next 记住,把目前的点 cursor 连到 newHead: 然后把 next 当作新的 cursor:把 cursor 当作新的 newHead 递归下去. 换句话说,每到一个点,把下一个点(右边的)记住,传到下一轮,然后把目前的点反向链接(向左链接). Java Solut…

Reverse a linked list from position m to n. Do it in one-pass. Note: 1 ≤ m ≤ n ≤ length of list. Example: Input: 1->2->3->4->5->NULL, m = 2, n = 4 Output: 1->4->3->2->5->NULL 根据经验,先建立一个虚结点dummy node,连上原链表的头结点,这样的话就算头结点变动了,我们还…

Reverse a linked list from position m to n. Do it in one-pass. Note: 1 ≤ m ≤ n ≤ length of list. Example: Input: 1->2->3->4->5->NULL, m = 2, n = 4 Output: 1->4->3->2->5->NULL 题意: 给定一个链表,反转第m~n个节点. 反转链表的一般思路 Solution1: 1.用指针找到…

Reverse a singly linked list. 做II之前应该先来做1的,这个倒是很简单,基本上不用考虑什么,简单的链表反转而已: /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */ class Solution { public: ListNode* rev…

翻译 反转一个单链表. 原文 Reverse a singly linked list. 分析 我在草纸上以1,2,3,4为例.将这个链表的转换过程先用描绘了出来(当然了,自己画的肯定不如博客上面精致): 有了这个图(每次把博客发出去后就会发现图怎么变得这么小了哎!仅仅能麻烦大家放大看或者另存为了.这图命名是1400X600的).那么代码也就自然而然的出来了: ListNode* reverseList(ListNode* head) { ListNode* newHead = NULL; wh…

翻转一个单链表.这个题目听说很多次了,总感觉肯定不是什么难题. 现在真的有点好高骛远了!总感觉那种很难的算法题才是难题,这种题没必要做.其实眼高手低啊. 这种easy题,我都不能一遍ac,这遇到白板编程也是挂的节奏! 仔细分析,每次翻转一个,要记录被反转的这个的前后节点. 1 -> 2 -> 3 -> 4 用p记录当前要改变其next指针的节点.last 指向前一个节点.pre指向后一个节点. 初始化,last = NULL. struct ListNode* reverse(struc…

本题要求将给定的单链表翻转,是校招面试手撕代码环节的高频题,能很好地考察对单链表这一最简单数据结构的理解:可以使用迭代和递归两种方法对一个给定的单链表进行翻转,具体实现如下: class Solution { public: ListNode* reverseList(ListNode* head) { return reverseList_iteratively(head); //return reverseList_recursively(head);//递归方法leetcode超时 } /…

原题地址:https://oj.leetcode.com/problems/reverse-linked-list-ii/ 题意: Reverse a linked list from position m to n. Do it in-place and in one-pass. For example:Given 1->2->3->4->5->NULL, m = 2 and n = 4, return 1->4->3->2->5->NULL.…

Reverse a linked list from position m to n. Do it in-place and in one-pass. For example:Given 1->2->3->4->5->NULL, m = 2 and n = 4, return 1->4->3->2->5->NULL. Note:Given m, n satisfy the following condition:1 ≤ m ≤ n ≤ lengt…

Reverse a singly linked list. 这题因为palindrome linked list 的时候需要就顺便做了一下.利用三个指针:prev, now, next 相互倒腾就行. /** * Definition for singly-linked list. * function ListNode(val) { * this.val = val; * this.next = null; * } */ /** * @param {ListNode} head * @retu…

①英文题目 Reverse a singly linked list. Example: Input: 1->2->3->4->5->NULL Output: 5->4->3->2->1->NULL ②中文题目 反转一个单链表. 示例: 输入: 1->2->3->4->5->NULL 输出: 5->4->3->2->1->NULL ③思路 用头插法(我暂时还不确定头插法是个啥,尾插法是个…

Given a singly linked list, return a random node's value from the linked list. Each node must have the same probability of being chosen. Follow up: What if the linked list is extremely large and its length is unknown to you? Could you solve this effi…

Given a linked list, determine if it has a cycle in it. To represent a cycle in the given linked list, we use an integer pos which represents the position (0-indexed) in the linked list where tail connects to. If pos is -1, then there is no cycle in…

Reverse a linked list from position m to n. Do it in one-pass. Note: 1 ≤ m ≤ n ≤ length of list. Example: Input: 1->2->3->4->5->NULL, m = 2, n = 4 Output: 1->4->3->2->5->NULL /** * Definition for singly-linked list. * struct…

Given a linked list, reverse the nodes of a linked list k at a time and return its modified list. k is a positive integer and is less than or equal to the length of the linked list. If the number of nodes is not a multiple of k then left-out nodes in…

问题: Reverse digits of an integer. Example1: x = 123, return 321 Example2: x = -123, return –321   Have you thought about this? Here are some good questions to ask before coding. Bonus points for you if you have already thought through this! If the in…

Reverse a singly linked list. 参考http://www.2cto.com/kf/201110/106607.html 方法1: 讲每个节点的指针指向前面就可以. /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */ class Solution…

题目 翻转链表 II 翻转链表中第m个节点到第n个节点的部分 样例 给出链表1->2->3->4->5->null, m = 2 和n = 4,返回1->4->3->2->5->null 注意 m,n满足1 ≤ m ≤ n ≤ 链表长度 挑战 在原地一次翻转完成 解题 九章中的程序 /** * Definition for ListNode * public class ListNode { * int val; * ListNode next;…