Book Image

PHP 7 Data Structures and Algorithms

By : Mizanur Rahman
5 (1)
Book Image

PHP 7 Data Structures and Algorithms

5 (1)
By: Mizanur 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)

Creating a double - ended queue (deque)

So far, we have implemented queues where one end is used for enqueuer, and is known as the rear, and the other end is used for dequeuer, and is known as the front. So, in general, each end should be used for a specific purpose. But what if we need to enqueuer and dequeuer from both ends? This is possible by using a concept called the double-ended queue or deque. In deque, both ends can be used for enqueue and dequeue operations. If we look at our queue implementation using linked list, we find that we can insert at last, insert at first, delete at last, and delete at first using our linked list implementation. If we implement a new deque class based on that, we can easily achieve our desired goals. The following figure depicts a double-ended queue:

Here is the implementation of a deque:

class DeQueue { 

private $limit;
private $queue...