Book Image

PHP 7 Data Structures and Algorithms

By : Rahman
5 (1)
Book Image

PHP 7 Data Structures and Algorithms

5 (1)
By: Rahman

Overview of this book

PHP has always been the the go-to language for web based application development, but there are materials and resources you can refer to to see how it works. Data structures and algorithms help you to code and execute them effectively, cutting down on processing time significantly. If you want to explore data structures and algorithms in a practical way with real-life projects, then this book is for you. The book begins by introducing you to data structures and algorithms and how to solve a problem from beginning to end using them. Once you are well aware of the basics, it covers the core aspects like arrays, listed lists, stacks and queues. It will take you through several methods of finding efficient algorithms and show you which ones you should implement in each scenario. In addition to this, you will explore the possibilities of functional data structures using PHP and go through advanced algorithms and graphs as well as dynamic programming. By the end, you will be confident enough to tackle both basic and advanced data structures, understand how they work, and know when to use them in your day-to-day work
Table of Contents (14 chapters)

Implementing a circular queue

When we use a standard queue, every time we dequeue an item, we have to re-buffer the whole queue. In order to solve this problem, we can use a circular queue, where the rear is followed by the front, forming a circle. This special type of queue requires a special calculation for the enqueue and dequeue operations, with consideration of the rear, front, and limit of the queue. Circular queues are always fixed queues, and are also known as circular buffers, or ring buffers. The following figure shows a representation of a circular queue:

We can implement a circular queue using a PHP array. Since we have to calculate the positions of the rear and front part, the array can be used efficiently for this purpose. Here is an example of a circular queue:

class CircularQueue implements Queue { 

private $queue;
private $limit;
private $front = 0...