Programmer Group

1. Why do you need a tree data structure? Analysis of array storage mode Advantages: it is fast to access elements by subscript. For ordered arrays, binary search can also be used to improve the retrieval speed.Disadvantages: if a specific value is to be retrieved, or the inserted value (in a certain order) will move as a whole, the eff ...

  Recently, in the study of react, vue is used in our work. In the process of learning, we compare the two to deepen our understanding.   The following is a small part of the knowledge points in react, which I personally think is also a common knowledge point. One of the ways of react component communication - routing parameters ...

WeChat official account: brother K crawler, QQ exchange group: 808574309, keep sharing crawler advance, JS/ Android reverse technology dry cargo! brief introduction When analyzing the JavaScript code of some sites, the simple code and functions are usually one by one, for example: function a() {console.log("a")} function b() {consol ...

Slow logs are mainly used to record SQL statements that take more than a specified time to execute in the database. Through slow query logs, you can find out which statements are inefficient for optimization. This paper briefly introduces the slow log structure in MySQL and TiDB, and deepens the understanding of the slow log structure of distri ...

Introduction to live broadcasting technology The live broadcasting technology covers a wide range. Now, it is widely known that the live broadcasting technology will be used in personal live broadcasting of video websites, mobile live broadcasting, security camera monitoring, etc. Introduce various technical links in the live broadcast proc ...

The value of a stock is equal to the discounted value of its future cash flow. ——Stock market rules 1, Foreword DCF(Discounted Cash Flow) is the abbreviation of discounted cash flow method, which can evaluate stocks. At present, most stock API s on the Internet only provide simple daily quotes, which is far from enough for analy ...

1, Input and output The first way: import java.util.Scanner; public class TestDemo { public static void main(String[] args) throws IOException { System.out.print("Enter a Char:"); char i = (char)System.in.read(); // Alt + ENTER System.out.println("your char is :"+i); } } The second way: 1. If an intege ...

1. Graph traversal 1.1DFS depth traversal (similar to the preorder traversal of binary tree) Idea: 1. To prevent multiple accesses, set the flag bit; Because there are many nodes, set an array and initialize all of them to 0. If the node has been accessed, set the corresponding subscript element to 1 2. Find the first edge of the current ...

In the previous article Third party payment interface design I left a question: Order timeout closed. This question is often asked in the interview. In this article, we will explain it. Similar scenarios to order timeout closing include: Taobao automatically confirms receipt;Wechat red envelopes have not been checked for 24 hours and need ...

1, What is the configparser module? The configparser module is a python standard library (which means it comes with Python and does not need to be installed). It can be used to operate configuration files with the suffix. ini. The format of the configuration file parsed by the configparser is similar to that of the. ini configuration file ...