Book Image

R Data Structures and Algorithms

By : PKS Prakash, Achyutuni Sri Krishna Rao
Book Image

R Data Structures and Algorithms

By: PKS Prakash, Achyutuni Sri Krishna Rao

Overview of this book

In this book, we cover not only classical data structures, but also functional data structures. We begin by answering the fundamental question: why data structures? We then move on to cover the relationship between data structures and algorithms, followed by an analysis and evaluation of algorithms. We introduce the fundamentals of data structures, such as lists, stacks, queues, and dictionaries, using real-world examples. We also cover topics such as indexing, sorting, and searching in depth. Later on, you will be exposed to advanced topics such as graph data structures, dynamic programming, and randomized algorithms. You will come to appreciate the intricacies of high performance and scalable programming using R. We also cover special R data structures such as vectors, data frames, and atomic vectors. With this easy-to-read book, you will be able to understand the power of linked lists, double linked lists, and circular linked lists. We will also explore the application of binary search and will go in depth into sorting algorithms such as bubble sort, selection sort, insertion sort, and merge sort.
Table of Contents (17 chapters)
R Data Structures and Algorithms
Credits
About the Authors
Acknowledgments
About the Reviewer
www.PacktPub.com
Preface

Hashing


Hashing is a different type of search technique, wherein the key values of the vector are directly accessed. It is a process of searching the element using some computation to map its key value to a position in the vector. The values of the vector can be placed in any order satisfying certain calculations rather than being based on any key value or their frequency of access. The function which performs the computation to map the key values to positions in a vector is termed a hash function, also denoted by h. The vector which holds the elements after the necessary calculations is termed a hash table (also denoted by HT), and its positions (or keys) are termed slots. The number of slots in a hash table is denoted by m, and each slot is numbered between 1 and m. The key objective of hashing is to arrange the elements in a hash table HT such that for any key value K and some hash function h, the slot in the hash table is defined as i = h(K), where i lies between 1 to m and the element...