• ## Pure jsp creates infinite levels of tree code

Time：2021-9-15

It’s not complicated to build a tree, but we usually do two or three layers. Such data usually comes from multiple tables, such as departments and employeesHowever, this self connected table, which has no definite hierarchy, may be infinite multi-levelFor example, a is the superior of B, B is the superior of C, and C […]

• ## Leetcode 1409. Query keyed permutation – Python

Time：2021-7-27

1409. Query keyed arrangement Three solutions Solution I violence class Solution: def processQueries(self, queries: List[int], m: int) -> List[int]: m = min(m, max(queries)) p = [i+1 for i in range(m)] ans = [] for x in queries: i = p.index(x) ans.append(i) x = p.pop(i) p.insert(0, x) return ans Solution two deque # from collections import […]

• ## Using Python to imitate a data visualization diagram of R language

Time：2021-7-20

The text and pictures of this article are from the Internet, only for learning and communication, and do not have any commercial use. If you have any questions, please contact us in time. The following article comes from Python big data analysis, written by fevrey   brief introduction To get to the point, the data […]

• ## One shell command a day Linux text operation series tree command

Time：2021-7-8

The tree command is the main role of printing files and directories in a graphical tree structure. Usually, this command is not included in Linux distributions. You need to use the package manager to install it yourself. example: 1. tree Print all files in the current directory 2. tree –p \${dir} Print all the files […]

• ## What is XML? Using XML to parse tree structure data

Time：2021-4-23

In real life, many things are related to each other. For example, there are many provinces in China, and there are many cities under each province. The relationship between these provinces can be described by a tree structure, as shown in Figure 1. Figure 1 city relationship Figure 1 visually describes the hierarchical relationship between […]

• ## Tree lists files in tree format

Time：2021-3-9

When you show others the contents of your own CD-ROM, or list the data in a directory on your hard disk, the tree command is quite convenient, and can make the contents displayed clear and orderly. Don’t say anything, picture above. By the way, review the CD command. Of course, you may not be satisfied […]

• ## The CMD tree command lists files in tree format

Time：2020-12-16

When you show others the contents of your own CD-ROM, or list the information in a directory on your hard disk, the tree command is quite convenient, and can let you display the content in a clear and orderly way. Don’t say anything, picture above. By the way, review the CD command.Of course, you may […]

• ## Implementation of custom tree structure by Vue

Time：2020-10-21

Implementation of custom tree structure by Vue It can be added and deleted dynamically It can be dragged as a whole If the content is also dynamic, replace the component content with input, select and other components data structure treeData: [{ name: ‘1’, child: [ { name: ‘2’, child: [{ name: ‘1’ }, { name: […]

• ## How to use the tree plug-in in CentOS

Time：2020-7-5

The tree plug-in consumes CPU and memory, so you need to pay attention when using it. Tree installation: yum -y install tree Or is it sudo apt-get install tree When using the directory name of tree, the tree structure of the directory can be displayed. An example is as follows: Unload command of treeyum -y […]

• ## Data structure tree (3): multiway search tree B tree, B + tree

Time：2019-12-14

Multiway search tree Height of complete binary tree: O (log2n), where 2 is logarithm The height of the complete m-path search tree: O (logmn), where m is the logarithm and the number of nodes in each layer of the tree M-path search tree is mainly used to solve the problem of data storage which can […]

• ## Using tree command to show the tree structure in MAC system

Time：2019-12-8

In Linux, you can easily use the tree command to view the directory tree mechanism in the current directory. But in MAC, you need to install at least one tool At first, I found a way to print tree structure with shell command from the Internet find . -print | sed -e ‘s;[^/]*/;|____;g;s;____|; |;g’ You […]

• ## Explain the use of tree command under Linux

Time：2019-10-3

Tree command, the main function is to create a list of files, all files listed in the form of a tree Tree under Linux is more powerful, but the general system does not have this command, it needs to be downloaded and installed manually. Installation: yum -y install tree – a Displays all files and […]