编程作业二 作业链接:Deques and Randomized Queues & Checklist 我的代码:Deque.java & RandomizedQueue.java & Permutation.java 问题简介 Write a generic data type for a deque and a randomized queue. The goal of this assignment is to implement elementary data struct…

1. 题目重述 完成三个程序,分别是双向队列,随机队列,和随机队列读取文本并输出k个数. 2. 分析 2.1 双向队列 题目的性能要求是,操作时间O(1),内存占用最大48n+192byte. 当使用单向链表时,尾端删除需要从链表头遍历,才能知道新的链表头,操作时间无法满足. 当使用变长数组时,当头尾均为1/4时,内存使用为~56N,不满足情况. 选用双向链表实现. 2.2 随机队列 题目性能要求时,操作时间O(1), 内存占用最大48n+192byte. 由于是随机操作,所以链表不适用,链表只…

实现一个泛型的双端队列和随机化队列,用数组和链表的方式实现基本数据结构,主要介绍了泛型和迭代器. Dequeue. 实现一个双端队列,它是栈和队列的升级版,支持首尾两端的插入和删除.Deque的API如下 public class Deque<Item> implements Iterable<Item> { public Deque() // construct an empty deque public boolean isEmpty() // is the deque emp…

RandomizedQueue 有几个关键点: 1. 选择合适的数据结构,因为需要任意位置删除元素,Linked list 做不到,必须使用resizing arrays. 2. resizing 的技巧. Q. How to grow array?    A. If array is full, create a new array of twice the size, and copy items.     Q. How to shrink array?     A: halve size…

本题的bonus是 因此方法是queue的size 达到了K, 就停止增加元素,保证queue.size() 最大时只有k. Java code: import edu.princeton.cs.algs4.StdIn; import edu.princeton.cs.algs4.StdOut; public class Subset { public static void main(String[] args){ int k = Integer.parseInt(args[0]); Rand…

本次作业考察利用array 或者linked list 实现规定时间复杂度的queue 和stack, 不能使用java 自带的stack 和queue. 目的是让我们掌握自己设计的函数的复杂度. Deque成功的关键是 1. 选择合适的数据结构,本题选择doubly LinkedList. 2. 自己写测试代码,测试各种情况.addLast, removeFirst 等等,尤其注意边界情况. Java code: //Deque - should be implemented using a…

1. Overview of Built-In Sequences Container sequences: list, tuple, and collections.deque can hold items of different types. Flat sequences: str, bytes, bytearray, memoryview, and array.array hold items of one type. Mutable sequences: list, bytearray…

作业原文:http://coursera.cs.princeton.edu/algs4/assignments/queues.html 这次作业与第一周作业相比,稍微简单一些.有三个编程练习:双端队列(Deque)设计.随机队列(Randomized Queue)设计,还有一个排列组合类Permutation. 一.双端队列Deque 设计要求:A double-ended queue or deque (pronounced "deck") is a generalization o…

Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. top() -- Get the top element. empty() -- Return whether the stack is empty. Notes: You may assume that…

Ring buffers and queues The data structure is extremely simple: a bounded FIFO. One step up from plain arrays, but still, it’s very basic stuff. And if you’re doing system programming, particularly anything involving IO or directly talking to hardwar…

工作队列 在第一篇教程中,我们已经写了一个从已知队列中发送和获取消息的程序.在这篇教程中,我们将创建一个工作队列(Work Queue),它会发送一些耗时的任务给多个工作者(Works ). 工作队列(又称:任务队列——Task Queues)是为了避免等待一些占用大量资源.时间的操作.当我们把任务(Task)当作消息发送到队列中,一个运行在后台的工作者(worker)进程就会取出任务然后处理.当你运行多个工作者(workers),任务就会在它们之间共享. 这个概念在网络应用中是非常有用的,它可…

Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. top() -- Get the top element. empty() -- Return whether the stack is empty. Notes: You must use only s…

RabbitMQ(一) -- Work Queues RabbitMQ使用Work Queues的主要目的是为了避免资源使用密集的任务,它不同于定时任务处理的方式,而是把任务封装为消息添加到队列中.而消息队列正是共享于多个工作者中使用,它们可以随意pop出数据进行处理. 消息的持久化 Message durability 为了保证`rabbitmq`意外重启等原因造成的消息丢失,通过设置消息的durable来实现数据的持久化,但是需要生产者和消费者同时设置持久化才能生效. 需要注意的是,`rab…

Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. top() -- Get the top element. empty() -- Return whether the stack is empty. Notes: You must use only s…

COMPUTER ORGANIZATION AND ARCHITECTURE DESIGNING FOR PERFORMANCE NINTH EDITION To do its job, the OS maintains a number of queues. Each queue is simply a waiting list of processes waiting for some resource. The long-term queue is a list of jobs waiti…

Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. top() -- Get the top element. empty() -- Return whether the stack is empty. Notes: You must use only s…

现如今移动设备也早已经进入了多核心 CPU 时代,并且随着时间的推移,CPU 的核心数只会增加不会减少.而作为软件开发者,我们需要做的就是尽可能地提高应用的并发性,来充分利用这些多核心 CPU 的性能.在 iOS 开发中,我们主要可以通过 Operation Queues.Dispatch Queues 和 Dispatch Sources 来提高应用的并发性.本文将主要介绍 Operation Queues 的相关知识,另外两个属于 Grand Central Dispatch(以下正文简称…

Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. top() -- Get the top element. empty() -- Return whether the stack is empty. Notes: You must use only s…

我对rabbitmq学习还不深入,这些翻译仅仅做资料保存,希望不要误导大家. You have consumers and producers under your belt, and now you’re itching to get started eh? Not so fast. First, you need to understand queues. Conceptually, there are three parts to any successful routing of an…

一.Implement Stack using Queues Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. top() -- Get the top element. empty() -- Return whether the stack is em…

232 - Implement Queue using Stacks Implement the following operations of a queue using stacks. push(x) -- Push element x to the back of queue. pop() -- Removes the element from in front of queue. peek() -- Get the front element. empty() -- Return whe…

Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. top() -- Get the top element. empty() -- Return whether the stack is empty. Notes: You must use only s…

题目描述: Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. top() -- Get the top element. empty() -- Return whether the stack is empty. Notes: You must use …

和RabbitMQ这个项目的缘分好奇怪,很长一段时间内是只关注源代码,真的是Erlang开源项目中的典范;现在要在项目中应用RabbitMQ,从新的视角切入,全新的感觉.仿佛旧情人换了新衣,虽是熟稔却有不曾领略的风情. RabbitMQ提供了一整套机制来处理消息的发送,接收,容错,管理,上一篇文章中我提到了一篇Rabbits and warrens的文章,是一篇非常棒的入门文章,但是里面忽略了不少细节,我沿着RabbitMQ in Action重新梳理了一遍,笔记于此,备忘. Exchanges…

1 简介 1.1 功能          Grand Central Dispatch(GCD)技术让任务并行排队执行,根据可用的处理资源,安排他们在任何可用的处理器核心上执行任务.任务可以是一个函数(function)或者是一个block. GCD的底层依然是用线程实现,不过这样可以让程序员不用关注实现的细节. GCD中的队列称为dispatch queue,它可以保证先进来的任务先得到执行通过它能够大大简化多线程编程.工程师只要将要执行的任务(执行代码块)放入队列中,GCD将会为需要执行的任…

1 题目 Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. top() -- Get the top element. empty() -- Return whether the stack is empty. **Notes:** You must u…

Comparing randomized search and grid search for hyperparameter estimation Compare randomized search and grid search for optimizing hyperparameters of a random forest. All parameters that influence the learning are searched simultaneously (except for…

Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. top() -- Get the top element. empty() -- Return whether the stack is empty. Notes: You must use only s…

In this blog, we give a solution for Quick Select. Here, we have an improvement. The idea is to randomly pick a pivot element. Main difference is how we implement partition. Java Random public int nextInt(int bound) Returns a pseudorandom, uniformly…

Question Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. top() -- Get the top element. empty() -- Return whether the stack is empty. Notes: You must u…