LeetCode & list cycle 链表是否存在环检测 singly-linked list 单链表 "use strict"; /** * * @author xgqfrms * @license MIT * @copyright xgqfrms * @created 2020-11-17 * @modified * * @description 链表 * @difficulty Easy Medium Hard * @complexity O(n) * @augme…

题目说明 Given a linked list, determine if it has a cycle in it. Follow up: Can you solve it without using extra space? 思路 一道比较出名的面试题,思路是用一个快指针,一个慢指针.快指针每次向前进两步,慢指针每次向前进一步.如果链表有环的话,快指针因为没法到达链表尽头迟早会和慢指针相遇,因此如果在到达链表尽头前两者相遇就表示链表有环路. 代码 public class LinkedLi…

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? 这个求单链表中的环的起始点是之前那个判断单链表中是否有环的延伸,可参见我之前的一篇文章 (http://www.cnblogs.com/grandyang/p/4137187.html). 还是要设…

Given a linked list, determine if it has a cycle in it. Follow up: Can you solve it without using extra space? 这道题是快慢指针的经典应用.只需要设两个指针,一个每次走一步的慢指针和一个每次走两步的快指针,如果链表里有环的话,两个指针最终肯定会相遇.实在是太巧妙了,要是我肯定想不出来.代码如下: C++ 解法: class Solution { public: bool hasCycle…

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? 解题思路,本题和上题十分类似,但是需要观察出一个规律,参考LeetCode:Linked List Cycle II JAVA实现如下: public ListNode detectCycle(Li…

问题描述如下: 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? 从问题来看,如果可以充分利用额外空间的话,这个题目是不难的,然而题目提出了一个要求,能否在不使用任何额外空间的情况下解决这个问题. 通过反复思考,我觉得这题类似于追击问题,可以用一个…

LeetCode解题报告:Linked List Cycle && Linked List Cycle II 1题目 Linked List Cycle Given a linked list, determine if it has a cycle in it. Follow up: Can you solve it without using extra space? Linked List Cycle II Given a linked list, return the node w…

Given a linked list, determine if it has a cycle in it. Follow up: Can you solve it without using extra space? 原题链接:https://oj.leetcode.com/problems/linked-list-cycle/ 题目:给定一个链表.推断它是否有环. 继续: 你能不用额外的空间解决吗? 思路:使用两个指针fast,slow,fast每次向前走两步,slow每次向前走一步.假设…

Problem: Given a linked list, determine if it has a cycle in it. Follow up:Can you solve it without using extra space? https://oj.leetcode.com/problems/linked-list-cycle/ Problem II: Given a linked list, return the node where the cycle begins. If the…

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? 原题链接:https://oj.leetcode.com/problems/linked-list-cycle-ii/ 题目:给定一个链表.返回环開始的节点.如无环.返回null. public L…