Book Image

Learning JavaScript Data Structures and Algorithms - Third Edition

Book Image

Learning JavaScript Data Structures and Algorithms - Third Edition

Overview of this book

A data structure is a particular way of organizing data in a computer to utilize resources efficiently. Data structures and algorithms are the base of every solution to any programming problem. With this book, you will learn to write complex and powerful code using the latest ES 2017 features. Learning JavaScript Data Structures and Algorithms begins by covering the basics of JavaScript and introduces you to ECMAScript 2017, before gradually moving on to the most important data structures such as arrays, queues, stacks, and linked lists. You will gain in-depth knowledge of how hash tables and set data structures function as well as how trees and hash maps can be used to search files in an HD or represent a database. This book serves as a route to take you deeper into JavaScript. You’ll also get a greater understanding of why and how graphs, one of the most complex data structures, are largely used in GPS navigation systems in social networks. Toward the end of the book, you’ll discover how all the theories presented in this book can be applied to solve real-world problems while working on your own computer networks and Facebook searches.
Table of Contents (22 chapters)
Title Page
Dedication
Packt Upsell
Contributors
Preface
Index

Greedy algorithms


A greedy algorithm follows the problem-solving heuristic of making the locally optimal choice (the best solution at the time) at each stage with the hope of finding a global optimum (global best solution). It does not evaluate the bigger picture like a dynamic programming algorithm does.

Let's take a look at how we can solve the min-coin change and knapsack problems we covered in the dynamic programming topic using the greedy approach.

Note

We covered some other greedy algorithms in this book in Chapter 12, Graphs, such as Dijkstra's algorithm, Prim's algorithm, and Kruskal's algorithm.

The min-coin change problem

The min-coin change problem can also be resolved with a greedy algorithm. Most of the time, the result is also optimal, but for some denominations, the result will not be optimal.

Let's take a look at the algorithm:

function minCoinChange(coins, amount) {
  const change = [];
  let total = 0;
  for (let i = coins.length; i >= 0; i--) { // {1}
    const coin = coins...