This article mainly introduces the greedy algorithm implemented in PHP, briefly explains the concept and principle of the greedy algorithm, and analyzes the relevant operating skills of the greedy algorithm implemented in PHP in the form of examples. Friends who need it can refer to it
The example in this article describes the greedy algorithm implemented in PHP. Share it with everyone for your reference. The details are as follows:
Background introduction: Greedy algorithm and data structure knowledge base algorithm can be said to be an algorithm closest to our lives. People are always greedy. Well, so the design of this algorithm is very consistent with human nature. The reason why I say this is because people will use greedy algorithms to solve problems intentionally or unintentionally in their lives. The most common thing is to make change. Everyone has never learned how to make change, but when there is enough money in all denominations, everyone will find the same combination to get the money they need. In fact, the greedy algorithm is at work here.
Design idea: The design idea of the greedy method can be understood from two aspects, namely intuitively and mathematically. Intuitively understanding the greedy algorithm is to use the fastest method to solve the problem. Here "fast" is the main goal. For example, in the above example of changing money, if the change you want to change is 6.6 yuan. Then first get a 5 yuan ticket, because this can make the money you collect grow the fastest. If the RMB has a denomination of 6 yuan, you will definitely choose the 6 yuan instead of using two other pieces to make up 6 yuan; mathematically understanding the greedy algorithm is to target the current optimal solution when making judgments, which is similar to optimization Steepest descent method in . The advantage of this method is that the problem solving speed is extremely fast, and it can basically be completed in one pass.
Algorithm defects: Just as a person cannot be too greedy, the greedy algorithm itself has fatal flaws, which places many restrictions on its application background. Because the algorithm takes the local optimal solution, it does not consider future problems. This is like a selfish person. Although he can get some benefits in a short time, it is difficult for him to achieve great achievements in the long run. Of course, society is very complex, and there may be people who continue to be selfish and live a pretty good life. This is reflected in the algorithm that in some cases (mentioned below), the greedy algorithm can obtain the optimal solution, which is of course a good thing for algorithm design.
/* * 贪婪算法 * $arr array 处理数组 * $volume int 盒子容量 */ function greedy($arr, $volume){ $box = array(); $boxNum = 0; $num = count( $arr ); for ($i = 0; $i < $num; $i++) { $boxCode = true; for ($j = 0; $j < $boxNum; $j++) { if ($arr[$i] + $box[$j]['v'] <= $volume) { $box[$j]['v'] += $arr[$i]; $box[$j]['k'][] = $i; $boxCode = false; break; } } if ($boxCode) { $box[$boxNum]['v'] = $arr[$i]; $box[$boxNum]['k'][] = $i; $boxNum++; } } return $box; }
The above is the detailed content of Implementation example of PHP greedy algorithm. For more information, please follow other related articles on the PHP Chinese website!

What’s still popular is the ease of use, flexibility and a strong ecosystem. 1) Ease of use and simple syntax make it the first choice for beginners. 2) Closely integrated with web development, excellent interaction with HTTP requests and database. 3) The huge ecosystem provides a wealth of tools and libraries. 4) Active community and open source nature adapts them to new needs and technology trends.

PHP and Python are both high-level programming languages that are widely used in web development, data processing and automation tasks. 1.PHP is often used to build dynamic websites and content management systems, while Python is often used to build web frameworks and data science. 2.PHP uses echo to output content, Python uses print. 3. Both support object-oriented programming, but the syntax and keywords are different. 4. PHP supports weak type conversion, while Python is more stringent. 5. PHP performance optimization includes using OPcache and asynchronous programming, while Python uses cProfile and asynchronous programming.

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.

PHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.

PHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip

PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values and handle functions that may return null values.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

Dreamweaver Mac version
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

WebStorm Mac version
Useful JavaScript development tools