Book Image

Python Data Structures and Algorithms

By : Benjamin Baka
Book Image

Python Data Structures and Algorithms

By: Benjamin Baka

Overview of this book

Data structures allow you to organize data in a particular way efficiently. They are critical to any problem, provide a complete solution, and act like reusable code. In this book, you will learn the essential Python data structures and the most common algorithms. With this easy-to-read book, you will be able to understand the power of linked lists, double linked lists, and circular linked lists. You will be able to create complex data structures such as graphs, stacks and queues. We will explore the application of binary searches and binary search trees. You will learn the common techniques and structures used in tasks such as preprocessing, modeling, and transforming data. We will also discuss how to organize your code in a manageable, consistent, and extendable way. The book will explore in detail sorting algorithms such as bubble sort, selection sort, insertion sort, and merge sort. By the end of the book, you will learn how to build components that are easy to understand, debug, and use in different applications.
Table of Contents (20 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
5
Stacks and Queues
7
Hashing and Symbol Tables

Doubly linked lists


Now that we have a solid grounding on what a singly linked list is and the kind of operations that can be performed on it, we shall now turn our focus one notch higher to the topic of doubly linked lists.

A doubly linked list is somehow similar to a singly linked list in that we make use of the same fundamental idea of stringing nodes together. In a Singly linked list, there exists one link between each successive node. A node in a doubly linked list has two pointers: a pointer to the next node and a pointer to the previous node:

A node in a singly linked list can only determine the next node associated with it. But the referenced node or next node has no way of telling who is doing the referencing. The flow of direction is only one way.

In a doubly linked list, we add to each node the ability to not only reference the next node but also the previous node.

Let's examine the nature of the linkages that exist between two successive nodes for better understanding:

With the existence...