1. Concept The full name of epoll is eventpoll, a notification mechanism based on event triggering. When the file descriptor read buffer is not empty, the read event is triggered. When the file descriptor write buffer is writable, the write event is triggered. 2. Principle The core data structure of epoll is: a red-black tree […]
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Call opencv library programming to display pictures and student ID names under Ubuntu
Article directory 1. Principle of Chinese character dot matrix font library (1), Chinese character encoding 1. Location code 2. Internal code (2) Dot matrix font structure 1. Bitmap font storage 2. 16*16 dot matrix font library 3. 1414 and 1212 dot matrix fonts (3). Acquisition of Chinese character lattice 1. Use location code to obtain […]
Call opencv library programming under Ubuntu to display a picture and display characters
? 1. Internal code, location code encoding rules and glyph data storage format of Chinese characters The in-machine code, location code encoding rules and glyph data storage format of Chinese characters are concepts related to Chinese character information processing. Here is a brief description: 1. Internal code: Internal code is the binary encoding used internally […]
JavaScript Library: jQuery, Simplified Programming
jQueryIntroduction Official website: https://jquery.com jQuery is a JavaScript Library . greatly simplified JavaScript Programming, for example JS Dozens of lines of native code to achieve the function able, jQuery It may be implemented in one or two lines, so it is widely used by front-end programmers. (Now in a relatively marginal state) Since its development, […]
Basketball timing and scorer design based on 51 microcontroller
Based on 51 microcontroller basketball timing and scoring device design (Simulation + Program + Circuit Diagram + Schematic + Design Report) Function introduction Specific functions: 1. It can record the game time of the entire schedule, and can modify and pause the game time. 2. The scores of the two teams in the schedule can […]
LC-1334. The city with the fewest neighbors within the threshold distance (Floyd algorithm, memorized search ==> dynamic programming (0x3f))
1334. The city with the fewest neighbors within the threshold distance medium There are n cities, numbered from 0 to n-1. Give you an edge array edges, where edges[i] = [fromi, toi, weighti] represents fromi and toi code> A bidirectional weighted edge between two cities, the distance threshold is an integer distanceThreshold. Returns the city […]
Volatile: The hidden hero of Java concurrent programming
: Just work hard and leave the rest to time : Xiaopozhan Volatile: The invisible hero of Java concurrent programming Preface First: Visibility Issues Second: Prohibit instruction reordering Third: Happens-Before relationship Fourth: Application cases Fifth: Comparison of Volatile, synchronized, and Lock Volatile: synchronized: Lock: Choose the appropriate tool: Sixth: Common misunderstandings and precautions Common misunderstandings: […]
jsp+servlet campus forum campus bbs (administrator, user) based on javaweb+mysql (java+jsp+servlet+mysql)
jsp + servlet campus forum campus bbs (administrator, user) based on javaweb + mysql (java + jsp + servlet + mysql) Private message Source code acquisition and debugging communication Operating environment Java≥8, MySQL≥5.7, Tomcat≥8 development tools eclipse/idea/myeclipse/sts, etc. can be configured to run Be applicable Course design, major assignments, graduation projects, project exercises, learning demonstrations, […]
Java GUI programming completes arithmetic test
1. Question requirements Write a small arithmetic test software to train primary school students’ arithmetic ability. The program consists of3classes, of which The Teacherclass object is responsible for giving arithmetic questions and judging whether the answer of the respondent is correct:ComputerFrameTheGUIinterface provided by the class object sees the question and passes it TheGUIinterface gives answers […]
“Amazon Cloud Technology Product Review” event call for papers｜Building a streaming media server with “weak” image processing functions
Authorization statement: This article authorizes the official Amazon Cloud Technology article to forward and rewrite the rights, including but not limited to Amazon Cloud Technology official channels such as Developer Centre, Zhihu, self-media platforms, third-party developer media, etc. This article is based on the following software and hardware tools: +awsec2 + frp-0.52.3 + mediamtx-1.3.0 + […]