Blue Bridge Cup -- timing scan matrix keyboard

1, Principle part Note: P36 to P42, P37 to P44, jumper cap connection 1 and 2 Key status scan There are two states of keys: one is pop-up state, the other is press state. Determine whether the key is pressed or bounced by judging the duration of the key state. Set a certain time to scan the stat ...

Posted on Thu, 16 Jan 2020 23:42:29 -0500 by packland

SqlServer common commands

Article directory 1, SQL Basics Two, enhance Three, function Four, actual combat 1.SELECT 2.Update 3. table / field 4. Index (add, delete, modify and check) Like 👍 pay attention ❤ don't get lost 1, SQL Basics 1.query SELECT Column name FROM Table name 2.Duplicate removal SELECT DISTINCT Colum ...

Posted on Thu, 16 Jan 2020 07:32:51 -0500 by kaumilpatel

Introduction to JPQ Integration Querydsl

_I don't know if you like or dislike using JPA. I really like not to tell me that JPA is not suitable for complex queries and so on. You need to know that all of them are micro-services now. As long as your server is split up sufficiently and the table design is reasonable, how many related queries can be transferred between services?And it com ...

Posted on Mon, 23 Dec 2019 21:58:36 -0500 by flyersman

Python crawler tutorial 22-100 CSDN college course data capture

1. CSDN college course data - written in the front Today, I'm going to grab a website again. I don't know who to start with because of my phobia. I'll look for it. Forget it, I'd better grab CSDN college. CSDN College's website is https://edu.csdn.net/courses I took a look at this website. The number of courses is not very large. There are abou ...

Posted on Mon, 09 Dec 2019 03:01:56 -0500 by Stripy42

Java drawing graphics in PDF documents

This document describes how to draw graphics in PDF documents by Java programming. Including drawing rectangle, ellipse, irregular polygon, line, arc, curve, sector and so on. In view of the ideas provided in the method, we can also transform the graphic design ideas by ourselves, such as diamond, trapezoid or combination graphics. Use tools: F ...

Posted on Mon, 02 Dec 2019 19:49:26 -0500 by clio-stylers

JAVA operation 4

Basic questions 15.1 What is an event source object? What is the event object? Describes the relationship between the event source object and the event object. The component that generates an event and triggers it is called an event source object An instance of an event source object is an event 15.4 please explain how to regist ...

Posted on Sun, 01 Dec 2019 17:40:51 -0500 by acidglitter

numpy&pandas: basic Python learning

Basic Python learning numpy & pandas Getting started with mofan python video At present, I am still studying for homework For data analysis and scientific calculation import numpy as np Idiomatic writing array = np.array([[1,2,3], [2,3,4]]) print(array) print(array.ndim) Matrix dimension (1,2,···) print(array.shape) Mat ...

Posted on Sat, 30 Nov 2019 19:46:33 -0500 by monstro

2c + +: new, delete exploration, overview of intelligent pointer, shared & PTR Foundation (Reprint)

new, delete new, delete is a keyword, like sizeof. Not a function new and delete do more than malloc and free. #include <iostream> #include <vector> using namespace std; class A { public: A() { cout <<"A structure"<<endl; } ~A() { cout <<"A Destructor of" &lt ...

Posted on Sat, 09 Nov 2019 14:49:29 -0500 by iceman2g

Analog processor scheduling

I. internship content Select a scheduling algorithm to achieve processor scheduling. II. Purpose of practice In a multiprogramming system, there are often several processes in readiness at the same time. When the number of ready processes is greater than the number of processors, it is necessary to determine which processes occupy the processor ...

Posted on Fri, 08 Nov 2019 08:57:25 -0500 by Roble

JAVA Foundation (object operation flow)

1. Objeccoutputstream is an object operation stream This stream can write out an object or read an object into a program, that is, it can perform serialization and deserialization. Serialization is to write (archive) according to the regulations of documents. To deserialize is to read (a file) according to ...

Posted on Fri, 01 Nov 2019 15:06:08 -0400 by Pigmaster