Programming VIP

In the previous article, I used openresty to build https proxy and log printing. With the passage of time, the openresty I built has been on the company's production server. A new problem appeared on Friday, so I began to explore! So what's the problem? How to solve it? Let's look down with questions! After this problem occurred, my collea ...

Basic experiment 4-2.1 isomorphism of trees Give two trees T1 and T2. If T1 can be changed into T2 through several child exchanges, we call the two trees "isomorphic". For example, the two trees given in Figure 1 are isomorphic, because after we exchange the left and right children of nodes A, B and G of one tree, we get another t ...

Operation database Operation database Several basic database operation commands: update user set password=password('123456')where user='root'; Change Password flush privileges; Refresh database show databases; Show all databases use dbname；Open a database show tables; show database mysql All tables in describe user; Display table mysql ...

Database MySql Basics 1. Function classification? What functions are often used? lower upper substr length Trim (remove the leading and trailing spaces and do not remove the spaces in the middle) str_to_date(%Y-%m-%d) date_format Format (decimal) round Random number ifnull (if empty, replace with 0) Aggregate function / grouping function Grou ...

True fragrance reason I'll just say one thing. If you want to restart a service of other servers, you can't build a conventional shell except for the expect method [if you're beaten, I'll delete it]Expect doesn't support any traversal syntax, so it's not too fragrant to use EOF to traverse expect [I don't know whether it's EOF or expect] ...

1. What is a data structure 1.1 some definitions of data structure "A data structure is a data object and the various relationships between the instances of the object and the data elements that make up the instance. These relationships can be given by defining relevant functions." Sartaj Sahni, data structure, algorithm and App ...

1, Operator 1.1 + -- addition of two objects +Operator is used to add two objects. [example 1] number addition. In Python, we often use + to add values. Common applications are as follows: a = 13 b = 2 c = 4.0 d = 5.0 print(a + b) # Add integers 15 print(c + d) # Floating point number addition 9.0 print(a + c) # Add integer and float ...

Standard Template Library: Standard Template Library( STL) Sequential container: vector, list. It is mainly used for iterative operations.Associated container: map, set. It is mainly used to quickly find the element value in the container. Generic algorithms provide many operations that can act on container classes and array types. T ...

Scrambling code of OFDM 1. Purpose In digital communication, if long 0 or 1 sequences often appear, it will affect the establishment and maintenance of bit synchronization. Using scrambling code in the transmitter can avoid the adverse effect of this data on the timing of the receiver. At the same time, in order to limit the crosstalk caused b ...

imgaug is a encapsulated python library for image authentication. It supports the transformation of key points and bounding box together. Project home page: imgaug doc 1. Installation and uninstallation # Install via github sudo pip install git+https://github.com/aleju/imgaug # Install via pypi sudo pip install imgaug # For local install ...