Tag:Number of columns

  • Sparse array


    For an array, if most elements are 0 or other same values and there are only a few different values, the array can be converted into a sparse array for storage, so as to reduce the size of the array and realize the function similar to compression. Convert to sparse array Take the conversion of […]

  • Golang 2D slice initialization


    Two dimensional slices are often used when doing some algorithm problems, so here is the method of creating two-dimensional slices for easy reference in the future. package main import “fmt” func main() { //Initialization method 1 row, column := 3, 4 var answer [][]int for i := 0; i < row; i++ { inline := […]

  • Opencv get image properties


    shape Shape can obtain the shape of the image and return tuples containing the number of rows, columns and channels.Grayscale: returns the number of rows and columnsColor: returns the number of rows, columns, and channelseg: import cv2 import cv2 Number of pixels Size can get the number of pixels of the imageGrayscale: Return: number of […]

  • Flutter learning notes (III) Muke technology fat teacher’s lecture notes


    4-1 establishment of basic structure of movie poster example code import ‘package:flutter/material.dart’; //Void is the main method with no return value, calling myapp, so pass the data here void main() => runApp(MyApp()); //Define a widget class MyApp extends StatelessWidget { final List<String> items; //The default parameter of the constructor is the key primary key, and […]

  • Flutter GridView Jiugong grid


    I have collected some learning materials, including a lot of learning, interview, middle and high-level fluuter materials, and a lot of video explanations. If any students want to know more, please see the end of the article for details. We also welcome all the great gods to install X. one   introduction GridView is one […]

  • Implementing waterfall flow with JavaScript


    Use js to realize waterfall flow and realize the function of scrolling not to the end. Of course, you can also add a judgment and set a value to terminate scrolling.(document. Body. Scrollheight < value) Pictures need to be added by yourself design sketch: code index.html <!DOCTYPE html> <html lang=”en”> <head> <meta charset=”UTF-8″> <meta name=”viewport” […]

  • Simulated matrix effect 2 (canvas experiment)


    I saw the effect of a CSS and JS application and practiced it. The demonstration is as follows:This time I played with canvas, and I felt pretty good,GitHub portal:https://github.com/EchoLsx/hackerDemo address:http://codepen.io/echo_lsx/pen/ZOaOyZ <canvas id=”c”></canvas> <!– Open source CDN is recommended to select external JS to be referenced // – > <script></script> /*Javascript code snippet*/ var c = […]

  • Merging cells based on element UI (dynamic data merging)


    1、 Frame name & version number Framework: element UI Version number: 2.3.9 or higher Portal: Element UI tab:https://element.faas.ele.me/#…Demo address:https://github.com/haryzxw/zx… 2、 Function description Realize the merging cell function of table, and merge the table horizontally and vertically 3、 Core code and comments Basic data example: Spanarr: [// merge coordinates, row is the row index, col is […]

  • Bash skill: shell script that can move Tetris up, down, left and right


    In Linux bash, the previous article introduced the shell script for displaying colored Tetris. Next, we will continue to introduce how to use the K, J, h, l keys to move a single box up, down, left and right. Script execution effect First, paste the specific execution screenshot of the shell script as follows: In […]

  • C # to convert TXT document to table


    C # implementation of TXT document conversion code: public DataTable TXTToDataTable(string fileName, string columnName) { DataTable dt = new DataTable(); FileStream fs = new FileStream(fileName, System.IO.FileMode.Open, System.IO.FileAccess.Read); StreamReader sr = new StreamReader(fs, System.Text.Encoding.Default); //Record one line of records read at a time string strLine = “”; //Record the contents of each field in each line […]

  • Front end tips: pure CSS to achieve waterfall flow (Mason)


    Waterfall flow provides a kind of beautiful layout, which is widely used by various material websites (such as:petal、unsplash)It is widely used. The community also provides many waterfall layout tools, such as:masonry 、colcadeAnd so on. The traditional way to realize waterfall flow is to use js to dynamically calculate the size and position of “bricks”, which […]

  • Write star right triangle with native JS


    right triangle:String traversal is done in ascending or reverse order Step idea:1. Number of outer loop rows traversed2. Traversing the number of outer loop columns3. Store characters4. Character wrap Requirement 1: downlink has one more character than uplink var str = ” For (VaR rows = 1; rows < = 5; rows + +) {// […]