题目连接 https://leetcode.com/problems/design-twitter Design Twitte Description Design a simplified version of Twitter where users can post tweets, follow/unfollow another user and is able to see the 10 most recent tweets in the user’s news feed. Your de…

https://leetcode.com/problems/design-twitter/ Design a simplified version of Twitter where users can post tweets, follow/unfollow another user and is able to see the 10 most recent tweets in the user's news feed. Your design should support the follow…

Design a simplified version of Twitter where users can post tweets, follow/unfollow another user and is able to see the 10 most recent tweets in the user's news feed. Your design should support the following methods: postTweet(userId, tweetId): Compo…

//先定义一个数据结构,代表一条微博,有两个内容:发布者id,微博id(代表微博内容) class TwitterData { int userId; int twitterId; public TwitterData(int userId,int twitterId) { this.twitterId = twitterId; this.userId = userId; } } //用一个map存储用户和各用户的关注用户 Map<Integer,Set<Integer>> use…

Design your implementation of the circular double-ended queue (deque). Your implementation should support following operations: MyCircularDeque(k): Constructor, set the size of the deque to be k.insertFront(): Adds an item at the front of Deque. Retu…

Design your implementation of the circular queue. The circular queue is a linear data structure in which the operations are performed based on FIFO (First In First Out) principle and the last position is connected back to the first position to make a…

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/design-twitter/description/ 题目描述 Design a simplified version of Twitter where users can post tweets, follow/unfollow another user and is a…

题目描述: Design a simplified version of Twitter where users can post tweets, follow/unfollow another user and is able to see the 10 most recent tweets in the user's news feed. Your design should support the following methods: postTweet(userId, tweetId):…

Design and implement a data structure for a compressed string iterator. It should support the following operations: next and hasNext. The given compressed string will be in the form of each letter followed by a positive integer representing the numbe…

https://leetcode.com/problems/design-linked-list/ Design your implementation of the linked list. You can choose to use the singly linked list or the doubly linked list. A node in a singly linked list should have two attributes: val and next. val is t…

原题链接在这里:https://leetcode.com/problems/design-hit-counter/description/ 题目: Design a hit counter which counts the number of hits received in the past 5 minutes. Each function accepts a timestamp parameter (in seconds granularity) and you may assume tha…

Design a search autocomplete system for a search engine. Users may input a sentence (at least one word and end with a special character '#'). For each character they type except '#', you need to return the top 3historical hot sentences that have pref…

Design a Phone Directory which supports the following operations: get: Provide a number which is not assigned to anyone. check: Check if a number is available or not. release: Recycle or release a number. Example: // Init a phone directory containing…

原题链接在这里:https://leetcode.com/problems/design-circular-deque/ 题目: Design your implementation of the circular double-ended queue (deque). Your implementation should support following operations: MyCircularDeque(k): Constructor, set the size of the dequ…

原题链接在这里:https://leetcode.com/problems/design-circular-queue/ 题目: Design your implementation of the circular queue. The circular queue is a linear data structure in which the operations are performed based on FIFO (First In First Out) principle and th…

原题链接在这里:https://leetcode.com/problems/design-tic-tac-toe/ 题目: Design a Tic-tac-toe game that is played between two players on a n x n grid. You may assume the following rules: A move is guaranteed to be valid and is placed on an empty block. Once a w…

Design a Tic-tac-toe game that is played between two players on a n x n grid. You may assume the following rules: A move is guaranteed to be valid and is placed on an empty block.Once a winning condition is reached, no more moves is allowed.A player…

Design a hit counter which counts the number of hits received in the past 5 minutes. Each function accepts a timestamp parameter (in seconds granularity) and you may assume that calls are being made to the system in chronological order (ie, the times…

Note: For the coding companion problem, please see: Encode and Decode TinyURL. How would you design a URL shortening service that is similar to TinyURL? Background:TinyURL is a URL shortening service where you enter a URL such as https://leetcode.com…

题目要求 Design a HashSet without using any built-in hash table libraries. To be specific, your design should include these functions: add(value): Insert a value into the HashSet. contains(value) : Return whether the value exists in the HashSet or not. r…

题目要求 Design a HashMap without using any built-in hash table libraries. To be specific, your design should include these functions: put(key, value) : Insert a (key, value) pair into the HashMap. If the value already exists in the HashMap, update the v…

这道题是LeetCode里的第707到题.这是在学习链表时碰见的. 题目要求: 设计链表的实现.您可以选择使用单链表或双链表.单链表中的节点应该具有两个属性:val 和 next.val 是当前节点的值,next 是指向下一个节点的指针/引用.如果要使用双向链表,则还需要一个属性 prev 以指示链表中的上一个节点.假设链表中的所有节点都是 0-index 的. 在链表类中实现这些功能: get(index):获取链表中第 index 个节点的值.如果索引无效,则返回-1. addAtHead(…

题目标签:HashMap 题目让我们设计一个 hashmap, 有put, get, remove 功能. 建立一个 int array, index 是key, 值是 value,具体看code. Java Solution: Runtime: 76 ms, faster than 27.53% Memory Usage: 58.2 MB, less than 31.57% 完成日期:03/18/2019 关键点:int array class MyHashMap { int [] map;…

题目标签:HashMap 题目让我们设计一个 hashset,有add,contains,remove 功能. 建立一个boolean array,index 是数字的值,具体看code. Java Solution: Runtime: 58 ms, faster than 90.21% Memory Usage: 56.3 MB, less than 68.53% 完成日期:03/18/2019 关键点:boolean array class MyHashSet { boolean [] se…

设计一个简化版的推特(Twitter),可以让用户实现发送推文,关注/取消关注其他用户,能够看见关注人(包括自己)的最近十条推文.你的设计需要支持以下的几个功能:    postTweet(userId, tweetId): 创建一条新的推文    getNewsFeed(userId): 检索最近的十条推文.每个推文都必须是由此用户关注的人或者是用户自己发出的.推文必须按照时间顺序由最近的开始排序.    follow(followerId, followeeId): 关注一个用户    un…

题目标签:Linked List 题目让我们自己设计一个 linked list,可以是单向和双向的.这里选的是单向,题目并不是很难,但要考虑到所有的情况,具体看code. Java Solution: Runtime:  56 ms, faster than 21.21% Memory Usage: 45.2 MB, less than 88.89% 完成日期:07/08/2019 关键点:edge cases public class ListNode { int val; ListNode…

355. 设计推特 设计一个简化版的推特(Twitter),可以让用户实现发送推文,关注/取消关注其他用户,能够看见关注人(包括自己)的最近十条推文.你的设计需要支持以下的几个功能: postTweet(userId, tweetId): 创建一条新的推文 getNewsFeed(userId): 检索最近的十条推文.每个推文都必须是由此用户关注的人或者是用户自己发出的.推文必须按照时间顺序由最近的开始排序. follow(followerId, followeeId): 关注一个用户 unfo…

题目 Design a HashMap without using any built-in hash table libraries. Implement the MyHashMap class: MyHashMap() initializes the object with an empty map. void put(int key, int value) inserts a (key, value) pair into the HashMap. If the key already ex…

二刷尝试了别的办法,用MAP代表关注列表. 然后不初始化,但是只要有用户被使用,而他又不在MAP里,就把他加进去,然后让他关注自己.. 但是这样做超时了. 问题在于这个题解法太多,有很多不同的情况. STACK记录所有推,然后找10个,那太难了,可能某个用户关注的只是几亿里面的某些人,搜索起来很要命. 那可以某人发推,就给所有关注他的人推一下.A关注B的时候,A刷新自己的推特队列,按时间顺序重新查找.这样比较符合现状,但是假如我有几亿关注者,每发一个就要刷新所有人的列表,这个还好.但是,每多一个…

刷题备忘录,for bug-free leetcode 396. Rotate Function 题意: Given an array of integers A and let n to be its length. Assume Bk to be an array obtained by rotating the array A k positions clock-wise, we define a "rotation function" F on A as follow: F(k…