Book Image

C++ Data Structures and Algorithms

By : Wisnu Anggoro
5 (1)
Book Image

C++ Data Structures and Algorithms

5 (1)
By: Wisnu Anggoro

Overview of this book

C++ is a general-purpose programming language which has evolved over the years and is used to develop software for many different sectors. This book will be your companion as it takes you through implementing classic data structures and algorithms to help you get up and running as a confident C++ programmer. We begin with an introduction to C++ data structures and algorithms while also covering essential language constructs. Next, we will see how to store data using linked lists, arrays, stacks, and queues. Then, we will learn how to implement different sorting algorithms, such as quick sort and heap sort. Along with these, we will dive into searching algorithms such as linear search, binary search and more. Our next mission will be to attain high performance by implementing algorithms to string datatypes and implementing hash structures in algorithm design. We'll also analyze Brute Force algorithms, Greedy algorithms, and more. By the end of the book, you'll know how to build components that are easy to understand, debug, and use in different applications.
Table of Contents (16 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Counting sort


Counting sort is a sorting algorithm that arranges items based on a key. Suppose we have an array containing unsorted items with a range between 0 to 9; we can sort it by counting the number of items based on the range as the key. Let's say we have an array of these items—{9, 6, 5, 6, 1, 7, 2, 4, 3, 5, 7, 7, 9, 6}. In a simple explanation, we just need to count the frequency of the occurrence of each item. We then iterate through the range from 0 to 9 to output the items in a sorted order. Initially, we will have an array containing the following items:

Now, we count the occurrence frequency of each item. Items 1, 2, 3, 4 will occur only once, items 5 and 9 occur twice, items 6 and 7 occur three times, and item 8 never occurs. This can be seen in the following diagram:

Based on this collection, we can reconstruct the array from the lowest item so that we end up with the following result:

Creating C++ code for counting sort is quite simple; we just need to prepare the counterArray...