Specify the number, sum, and minimum of arrays to get a set of random numbers

Specify the number, sum, and minimum of arrays to get a set of random numbers The original requirements are as follows: Given sum SUM(A), given minimum number M, given length S of sequence, and precision P of each number in sequence, It is required that each number in the sequence must meet the requirements of a > = m, accur ...

Posted by Kev on Sat, 04 Apr 2020 11:43:31 +0200

php design pattern observer pattern

In web applications, generally, some small-scale data and business changes, and other relevant business data also need to change. In this case, observer pattern is very suitable. Observer mode is usually implemented by using an interface called observer. If other classes want to introduce observers, they need to implement this interface For e ...

Posted by aron on Sat, 04 Apr 2020 01:01:23 +0200

The UTF-8 coding problem of Jenkins

Jenkins is easy to get cramped sometimes. I configured the code in tomcat, which is not easy to use. I started because of the problem of nginx's reverse proxy, but later found out that Tomcat became a demon. The solution is to copy my Tomcat configuration, and then add parameters and modify on my basis. Error screenshots ...

Posted by rfrid on Thu, 02 Apr 2020 22:30:04 +0200

Powerful and elegant list derivation expression in python

The derivation expression is actually to simplify some loop judgment operations, etc How many ways can you generate a list of numbers 1-10? >>> l = [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ] >>> l [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] >>> >>> l = [] >>> for x in range( 1, 11 ): ... l.append( x ) ...

Posted by tinuviel on Thu, 02 Apr 2020 21:38:33 +0200

BZOJ4710: [Jsoi2011] special products (principle of tolerance and exclusion + combinatorial mathematics + DP)

Title gate: http://www.lydsy.com/JudgeOnline/problem.php?id=4710 Topic analysis: at first, I didn't have a clue at all. Later, I found out that this is just like the second kind of stirling number? First of all, consider how to do without the condition that everyone should take at least one specialty. Because different speci ...

Posted by Paulkirkewalker on Tue, 31 Mar 2020 19:10:03 +0200

Detailed explanation of PHP FFI -- a new PHP extension method

  With PHP7.4, there is an extension that I think is very useful: PHP FFI (Foreign Function interface), which refers to a description in PHP FFI RFC: For PHP, FFI provides a way to write PHP extensions and bindings to C libraries in pure PHP. Yes, FFI provides high-level languages to call each other directly. For PH ...

Posted by Johan Beijar on Mon, 30 Mar 2020 12:07:14 +0200

PHP Clean Code (Part 2)

PHP Clean Code (Part I) Use default parameters instead of short circuit operation or condition judgment Bad practice: This is not good because $breweryName can be NULL function createMicrobrewery($breweryName = 'Hipster Brew Co.'): void { // ... }    It's OK: This approach is easier to understand than the above, but it needs to contr ...

Posted by Kiubbo on Fri, 27 Mar 2020 11:33:02 +0100

PHP Clean Code (Part 1)

introduce Software Engineer Guidelines for Robert C.Martin's Clean Code The same applies to PHP.It is not a guide to coding style, it guides us to write readable, reusable, and decomposable code in PHP. Not all guidelines must be strictly followed, even some have become common conventions.This is just a guideline, many of which are years of ex ...

Posted by Kalland on Fri, 27 Mar 2020 09:16:14 +0100

solidity test case practice

Truffle development framework provides two methods for testing Ethereum smart contract: solid testing at blockchain level and JavaScript testing at DApp level. In this tutorial, we will introduce the purpose, difference and application scenario of these two testing methods of Ethereum smart contract, and learn how to use the solid test case and ...

Posted by Demonic on Thu, 26 Mar 2020 04:11:33 +0100

Actual Ethereum smart contract test [Truffle]

Truffle development framework provides two methods for testing Ethereum smart contract: solid testing at blockchain level and JavaScript testing at DApp level. In this tutorial, we will introduce the purpose, difference and application scenario of these two testing methods of Ethereum smart contract, and learn how to use the solid test case and ...

Posted by scheols on Thu, 26 Mar 2020 03:33:25 +0100