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)

Finding the shortest path using the Bellman-Ford algorithm

Though Dijkstra's algorithm is the most popular and efficient one that is used to find the single source shortest path, there is one problem that it does not address. If the graph has a negative cycle, Dijkstra's algorithm cannot detect the negative cycle, and, thus, it does not work. A negative cycle is a cycle where the sum of all the edges in the cycle is negative. If a graph contains a negative cycle, then finding the shortest path will not be possible, so it is important that we address the issue while finding the shortest path. That is why we use the Bellman-Ford algorithm, even though it is slower compared to Dijkstra's algorithm. Here is the algorithm pseudocode for the Bellman-Ford algorithm for the shortest path:

function BellmanFord(list vertices, list edges, vertex source) 
// This implementation...