Articles
android

Four solutions to AC this hard problem: from "naive solution" to "area difference" method | Java

This article is participating in the "Java Topics month - Java brush title punch" to view details about active links Title description This is the LeetCode 42. The rainwater , the difficulty is difficult . Tag: "Monotone Stack", "Mathematics" Given n non-negative integers representing the height map of each column with a width of 1, calculate how much rain can be received by the columns arranged in this way after it rains. Example 1: Input: height = [0,1,0,2,1,0,1,3,2,1,2,1] Output: 6 Explanatio

... Vivian
schedule 10 min read
android

Three ways to create threads

Three ways to create threads 1. Inherit the Thread class public class ThreadTest01 extends Thread {     @Override     public void  run () {         for  (int i = 0; i <10; i++) {             System.out.println( "run--->"  + i);         }     }     public stat

... Alejandro
schedule 15 min read
android

Crawler combat (2) Use Python to crawl Netease cloud playlist

Recently, the blogger has fallen in love with listening to music, but is suffering from not being able to find good music, so he plans to go shopping in NetEase Cloud s playlist In line with the idea of "using technology to change life", I thought of writing a crawler to crawl NetEase Cloud's playlist and sort it automatically according to the amount of play. In this article, we will talk about how to crawl the NetEase Cloud playlist and sort the playlist according to the amount of play. The ren

... Avery
schedule 8 min read
android

(Essence) Use of Ocelot Microservice API Gateway on September 25, 2020

API gateway Concept------why------how to use oclet-----internal concepts (upstream and downstream), routing-----ocelot internal operating principle-----how to do steps-- ---Introduction to ocelot configuration file----Basic use of routing----Routing load balancing------Routing consul support-----Routing multiple service operations-----Routing multiple service aggregation ----Route current limit----Route fuse----Route cache----Route authentication. What is an API gateway It is used to restrict th

... Faith
schedule 11 min read
android

Digital Transformation Writing Notes-Day 42

Write a book diary Continue to study, and then write, today it has exceeded 160,000 words, and there are two final chapters. Part: For this purpose, we have opened a special digital transformation private board meeting to discuss this issue, and the essence of the discussion is organized. It is in the fifth section of Chapter 1, I must have read it. Although there are a lot of things mentioned above, and the methodology seems to be quite reasonable, what should we do specifically? In fact, wheth

... Ashley
schedule 3 min read
coder_life

[Filtering tracking] Matlab source code for track filtering tracking based on EKF, UPF, PF, EPF, UPF multiple Kalman filters

1. Purpose of using Kalman filter       Let's assume that you have built a small robot that can walk in the woods. In order to navigate accurately, the robot needs to know its own location at all times.       We use symbols to represent the state variables of the robot. Here we assume that the state variables only contain the position and speed of the robot:       , , , ( , , ).       , , GPS. GPS

... Logan
schedule 15 min read
coder_life

The long essay tells how I sent Tsinghua University to Tsinghua|The struggle history of underachievers

About the author: Program Yuanshishi (ID: tangleithu), from the 18th-line impoverished rural area ( check my counterattack road ), a BAT factory P7, is the former technical director of DJI (drone), used to be a startup company Have stayed, have a wealth of experience. This article was first published on WeChat official account, the original link , please keep the full text if reprinted. Backstage reply to the keyword "1024" to obtain the interview guide for programmers. background Hello everyon

... Eli
schedule 47 min read
coder_life

Twelfth Blue Bridge Cup C/C++ B Group E Question Path: Solution|Check in

This article is participating Nuggets team number on-line activity, click to see giant spring recruit jobs 1. Title description: The question I m going to write today is the E question path of the 12th Blue Bridge Cup C/C++ B group freshly released today. Many people on the Internet say that this year s question is a lot more difficult, but most of the questions are still examined Classic simple algorithm, such as this question. The main idea of the topic: a total of 202120212 0 2 1 points, labe

... Max
schedule 6 min read
coder_life

After 00, programmers have worked hard for nearly a year, and have summarized the following 7 life suggestions for students (recommended collection)

Preface         Hello everyone, I am a post-00 programmer born in the millennium. Due to a very special personal reason, I have graduated and have been in the workplace for a year. In the continuous exploration of society for nearly a year, I have understood a lot of life philosophy and seen through a lot of human reality. With the help of this sharing, I sorted out the themes in the following aspects, I hope it will be helpful to you, and avoid detours on

... Daisy
schedule 23 min read
coder_life

STM32 Chapter 9-IIC Communication Application

Speaking of IIC (usually called I2C, in fact, they are all the same) communication is the simplest communication protocol. When learning STM32, the first contact is the serial port USART communication protocol, the next is the IIC communication protocol, and the other is the SPI protocol. We will talk about SPI in the next chapter, and this chapter will talk about IIC. Many modules have used IIC communication, the most common is the 4-pin 0.96 inch OLED display. Of course, when learning STM32,

... Faith
schedule 27 min read
dev_tools

Computer Basics

Five-layer Internet Protocol Stack: Application layer (dns, http) DNS resolves to IP and sends http request The transport layer (tcp, udp) establishes a tcp connection (three-way handshake) Network layer (IP, ARP) IP addressing Data link layer (PPP) encapsulation and framing Physical layer (using physical media to transmit bit streams) Physical transmission (then transmit through various media such as twisted pair wires, electromagnetic waves, etc.) OSI seven-layer framework: Physical layer: bi

... Alyssa
schedule 78 min read
dev_tools

Talk about the implementation principle behind the Unity coroutine

Unity development inevitably needs to use coroutines. The feature of coroutine synchronous code for asynchronous tasks allows programmers to get rid of the previous coding method of asynchronous operations and callbacks, making the code logic more coherent and easy to read. However, while being surprised at the usefulness and magic of the coroutine, because I don't know the implementation principle behind the coroutine, I always feel that I cannot fully grasp the coroutine. such as: MonoBehaviou

... Daniel
schedule 14 min read
dev_tools

The world of CSS selectors: mastering CSS selectors

CSS selectors currently have the following: descendant selector space (), sub-selector arrow (>), adjacent sibling selector plus (+), subsequent sibling selector Wanwan (~), and column selector double Pipe (||). For the first four selectors, the browser supports them earlier and is very practical, which is the focus of this chapter. The last column selector is considered "upstart", which is closely related to the layout of Table and other layouts, but the current browser compatibility is not

... Patrick
schedule 30 min read
dev_tools

Redux Must Manual, Part 4: Using Redux Data

Introduction Part 3: Basic Redux data flow , we learned how to start with an empty Redux + React project setup, add a new state slice, and create React that can read data from the Redux store and dispatch actions to update the data Components. We also studied how data flows in the application, components dispatch actions, reducers process actions and return new state, and components read new state and re-render the UI. Now that you know the core steps of writing Redux logic, we will use the same

... Eric
schedule 28 min read
dev_tools

The second course of deep learning notes improves deep neural networks. The third week of hyperparameter debugging, Batch regularization and program framework...

This article is the notes part of teacher Wu Enda's deep learning course [1]. Author: Huang Haiguang[2] Main writers : Huang Haiguang, Lin Xingmu (all the manuscripts of the fourth lesson, the first two weeks of the fifth lesson, and the first three quarters of the third week), Zhu Yansen: (all the manuscripts of the third lesson), He Zhiyao (the third week of the fifth lesson), Wang Xiang, Hu Hanwen, Yu Xiao, Zheng Hao, Li Huaisong, Zhu Yuepeng, Chen Weihe, Cao Yue, Lu Haoxiang, Qiu Muchen, Ta

... Jude
schedule 78 min read
programming

Asynchronous application of ES6(13)Generator

basic concepts Coroutine: multiple threads cooperate with each other to complete asynchronous tasks A coroutine is a bit like a function, but also a bit like a thread. Its running process is roughly as follows: In the first step, the coroutine A starts to execute. In the second step, the execution of coroutine A is halfway through, enters a pause, and the execution right is transferred to coroutine B. In the third step, (after a period of time) Coroutine B returns the execution right. In the fou

... Aubrey
schedule 14 min read
programming

nodejs-set permissions

Preface log in Register registered Check if the user exists check The user has a prompt registration failure, User does not exist to perform registration Copy code Add new user log in Check if the user exists Verify username and password Return logo The cookie exists on the client side, and the security is not high The session exists on the server, which has high security. Once the service is hung up, the data will be lost The token exists in the server, and it stores a set of algorithms, which

... Isaac
schedule 11 min read
programming

flask- marshmallow serialization and deserialization

Official document: marshmallow.readthedocs.io/en/latest/ marshmallow (cotton candy) is a lightweight data conversion module, also called serialization (converting P data model objects into storable or transferable data types) and deserialization (converting transferable data types into data Model object) Serializing Serialization can convert data model objects into storable or transferable data types, for example: objects/object->list/dict, dict/list->string Deserialization (deseriazing) T

... Kai
schedule 27 min read
programming

100 Examples of Deep Learning-Convolutional Neural Network (CNN) Weather Recognition | Day 5

1. Preliminary work This article will use CNN to recognize four weather states: cloudy, rainy, sunny, and sunrise. Compared with the previous article, in order to increase the generalization ability of the model, this article added a dropout layer and adjusted the maximum pooling layer to an average pooling layer. My environment: Language environment: Python3.6.5 Compiler: jupyter notebook Deep learning environment: TensorFlow 2.4.1 Recommended reading: 100 cases of deep learning-convolutional n

... Alyssa
schedule 9 min read
programming

Why choose TypeScript?

Add a follower, don t miss the follow-up updates~ Authorized by the author, this article is translated and summarized from the personal blog "Understanding TypeScript's Popularity" of a member of the TypeScript Team orta. Original author: orta Original link: orta.io/notes/js/wh... Translation: ycaptain TypeScript is a very popular JavaScript language extension. It adds a type layer on top of the existing JavaScript grammar, and even if this layer is deleted, it will not affect the original perf

... Riley
schedule 16 min read
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