• MySQL index, why B + instead of balanced binary tree


    Why do databases use B + trees? preface When it comes to indexing, the first reaction is definitely to improve query efficiency. For example, if you want to find a chapter in a book directory, you will first locate it from the directory. If you don’t have a directory, you need to look through everything […]

  • Data structure: Union Search


    1、 Introduction Union search is a unique data structure, which is a tree structure from child node to father node. It can solve the connectivity problem efficiently Connectivity issues Note: the above figure is a connection problem. If the two points in the upper left corner are directly connected, the naked eye can give a […]

  • [flutter 2-9] flutter handle tutorial UI layout and widget — flexible layout control


    Author: VladSource Vlad (official account: fulade_ me) Flexible Flexible can help the child controls of row, column and flex fill the parent controls. It is flexible in usage and has weight properties. Similar to flexible controls are expanded.Let’s see firstFlexibleConstructor for const Flexible({ /// key Key key, //The default value of flex is 1 this.flex […]

  • AVL (balanced binary tree) of data structure


    1、 Introduction AVL tree is a self balanced binary search tree. When adding or deleting, it determines the left and right rotation operation according to the balance factor (the height difference between the left and right subtrees), so as to rebalance the trees that may be destroyed, and ensure the query efficiency of AVL trees. […]

  • This front end uses dynamic programming to write waterfall flow layout? Kill him!


    preface Waterfall flow layout is a common requirement in the front-end field. Because the height of the image is inconsistent, it is difficult to get a satisfactory arrangement in the default layout of multi column layout. Our demand is that in the case of irregular picture height, in the two column layout, the total height […]

  • One of the functions of line height


    HTML structure: <div class=”money-options active”> < p class = “TXT” > monthly membership</p> <p class=”money”>¥XX</p> < p class = “times” > 1 month</p> </div> CSS structure: .money-options { display: inline-block; width: 106px; height: 108px; /*Line height: 1; * // * when there is no line height*/ margin-right: 10px; border: 1px solid #D7D7D7; border-radius: 8px; text-align: […]

  • How to realize the autoheight function of textarea


    This function is also quite common. It is used to obtain the length and width of the text (to avoid the problem of inaccurate calculation). It is mainly used to realize the automatic lengthening of the textarea. We can see that when we use textarea, sometimes we need to perceive the height of the content […]

  • Vertical and horizontal scrolling of better scroll:


    Vertical and horizontal scrolling of better scroll: preface: Recently I learned Vue, In doing a small project exercise, you need to use better scroll to achieve smooth rolling effect. At the beginning, you only know that it can achieve vertical rolling (I’m ignorant of / (ㄒㄒㄒㄒ) / ~ ~), and then you need to realize […]

  • Vue and H5 solve the problem that the soft keyboard of Android phone pops up and the page height is raised


    Tested, problem solved const originalHeight=document.documentElement.clientHeight ||document.body.clientHeight; window.onresize = ()=>{         return(()=>{                     //The height of the window will change when the keyboard pops up or hides const resizeHeight=document.documentElement.clientHeight || document.body.clientHeight; console.log (enter to judge page height = = = = = =); console.log (“initial page height = […]

  • Are you serious about height design in responsive web pages?


    Author: Ahmad ShadeedTranslator: XiaozhiSource: ishadeed Like again, form a habit this paperGitHubhttps://github.com/qq44924588… I’ve collected more categories of previous highly praised articles and sorted out a lot of my documents and tutorial materials. Welcome star and perfect, you can refer to the interview site review, I hope we have something together. Recently, a Vue component is […]

  • Baidu ecarts angular packaging


    preface In recent projects, visual charts are needed, which is just rightechartsWhen you release a new version, you chooseechartsAs the base chart library. howevergithubBased onechartsMost of the encapsulation is based on2.XThe encapsulation of the version is inconsistent with the project. be based on3.0+Version ofhttps://github.com/liekkas/ng-echartsBut the way of use is not consistent with my idea, so […]

  • Questions about novices


    1、 When the parent element floats, the child element floats, and the child element can support the parent element. When we set the floating attribute, we will naturally clear the floating in our mind, but we will find that when the parent element has floating or uses absolute positioning, the floating child element can support […]