• ## Example of head command in Linux system

Time：2022-4-1

• ## Sword finger offer plan 5 (medium version of search algorithm) — Java

Time：2022-3-10

1.1 topic 1 Sword finger offer 04 Find in 2D array 1.2 solution In fact, it’s an upgraded version of the violent solution. Judge from the last line, through the current size of num, If it is still greater than the target value, the number of rows is – 1; if it is less than, […]

• ## Leetcode-006-zigzag transformation

Time：2022-2-13

Zigzag transformation Title Description: arrange a given string s in a Z-shape from top to bottom and from left to right according to the given number of lines NumRows. For example, when the input string is “paypalishing” and the number of lines is 3, the arrangement is as follows: P A H NA P L […]

• ## Summary | powerful dplyr package (I) (required)

Time：2022-1-29

Tweets shared with you in previous periodsSummarize some important r packages in the steps of data sorting, analysis and visualizationIn, we introduce a data processing package: dplyr. Dplyr package can handle structured data inside or outside R, and help you solve most data processing problems. This package has many functions and powerful functions. I will […]

• ## Line number control skills of uilabel

Time：2022-1-2

The number of rows of uilabel is controlled, for example, 2 rows are displayed First, everyone will: label.numberOfLines = 2 The second type can be controlled by font size and label size label.font = UIFont.semibold(ofSize: 16) label.frame.size = // … coordination label.numberOfLines = 0 After designing according to the second method, The first two effects […]

• ## Sparse array

Time：2021-11-26

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 […]

• ## Introduction to fast JDBC

Time：2021-11-16

This paper introduces an open source JDBC operation tool class fastjdbc and a JDBC rapid development kit based on springboot frameworkIn fact, it is a secondary encapsulation of the namedjdbctemplate class provided by the spring framework. It provides an API configuration method based on annotation to operate SQL, rather than calling the namedjdbctemplate method to […]

• ## My toolbox (I) – git project submission line count script

Time：2021-10-10

At work, I often need to pay attention to a lot of information.Working on git projects, I usually focus on who submitted a certain submission record and what has been changed. However, it’s interesting to think about some hidden data when you jump out of pure development work.One of the most intuitive data is the […]

• ## The function of adding rows and storage space in a statistical table every day

Time：2021-10-10

Use the code provided in the article to make a statistical table, the number of new rows per day and the function of new storage space The implementation steps are as follows: 1. Create table Create a table to store the table space usage every day CREATE TABLE [dbo].[t_rpt_table_spaceinfo]( [table_name] [sysname] NOT NULL, [record_date] [date] […]

• ## MySQL show status command details

Time：2021-9-27

Show status server status item introduction Status name Scope explicate Aborted_clients Global The number of connections interrupted because the client terminated because the client did not close the connection properly Aborted_connects Global The number of failed connections attempting to connect to the MySQL server Compression Session Only compression protocol is enabled between client and server […]

• ## Leetcode-6-zigzag transformation

Time：2021-9-23

1： Title: A given string is arranged in zigzag from top to bottom and from left to right according to the given number of lines. For example, when the input string is “leetcodeishing” and the number of lines is 3, the arrangement is as follows: L C I R E T O E S I […]