Data structures and algorithms are a black box topic for non-software engineers. These tools are the magic of what makes apps and websites run and run well. While they offer engineers immense power, the most used data structures and algorithms are simple and may take days or weeks to learn, not years.
It does take some time to learn how data structures and algorithms work and how to apply them, but having the best resources will allow you to master them quickly. Let's look at some of the best resources for mastering data structures and algorithms.
Why Data Structures and Algorithms Knowledge Matter
Before we discuss the best resources, let us talk about how knowing data structures and algorithms matters. To demystify these terms, let us assign basic definitions. Data structures are items to create and store data. This could be as simple as an array of string-type objects or as complex as a multi-level nested JSON object.
Algorithms are actions performed on a piece of data, or input, to produce a desired output. A simple algorithm may take a lowercase word like apple and titleize it to Apple. Algorithms get more complex as you wish to do more complex actions or perform actions on more complicated pieces of data.
With these definitions, we can see why understanding the possible options for storing data and the benefits of these structures is very important to know. Sure, you could store data in any format, but will you want to traverse a doubly linked list to access the second item of a submitted form field? Probably not.
It is important to understand algorithms as time and space in programming matter. You only have so much local space to store data that you are working on before your machine becomes unresponsive. You also only have so much time to manipulate and retrieve data before a user gets impatient or a server times out. Understanding different algorithm design patterns and time and space complexity is crucial to writing great software.
The reason that these two topics are tested in interviews is that they prove that the potential hire has an understanding of what good programming is. A common misconception with software engineering is that finding a solution is difficult. Getting the correct solution is tricky, and understanding the best structures and methods to manipulate data matters.
Being good at answering these questions is a skill more than inherent talent. You may know how a binary tree is built or how to solve common recursive problems; however, acing interviews requires practice. Let's talk about some great resources to practice and expand your knowledge of data structures and algorithms.
LeetCode (Online Practice Platform)
We will start our journey into data structures and algorithms with a set of online practice platforms. At this point, the online technical practice problem platform, LeetCode, is synonymous with data structures and algorithms and technical coding challenges. It has a well-designed, structured, and curated selection of interview and technical questions.
You can sort for questions by data structure type or algorithm type to allow you to really focus on mastering a specific topic. They even sort their questions by company. If you are preparing for an interview at Google, Meta, or Amazon, you can practice questions previously asked in company interviews.
One of the most valuable features of the LeetCode platform is its collection of user-generated solutions. There are many ways to solve a question, each with specific syntax and efficiency. Seeing many code solutions can help you better understand how or how not to approach a question.
Understanding these different approaches will help you show mastery of topics during an interview. By being able to point out why you did not choose a specific solution, you demonstrate that you are not just memorizing answers. Overall LeetCode is an excellent platform for practicing and mastering data structures and algorithms.
Hacker Rank (Online Practice Platform)
Our second data structures and algorithms resource may not have the structure of company-specific questions LeetCode has but offers its own benefits. Hacker Rank is another online platform for learning and practicing data structures and algorithms. It has the perk of being a common platform for software engineering technical interviews.
This platform has perfected the art of assigning technical interviews to potential software engineering hires and is commonly used by recruiters. It helps to get familiar with an interview platform before taking interviews. This is a great option to get some practice before you are tested in a real-world interview.
Codewars (Online Practice Platform)
This learning platform is similar to Hacker Rank or LeetCode in that it offers sets of programming questions but does so in a more fun manner. You can solve Kata or challenges, which earns you kyu. Gaining kyu advances your ranking as a programmer. Solving the more difficult questions gives you more kyu helping you obtain higher prestige.
This platform lacks some of the functionality of Hacker Rank as a simulator for actual remote technical assessments and the robust solutions of LeetCode. However, it shakes things up and presents the questions in a fun way which is a great way to make a somewhat tedious task fun.
Udemy Courses (Online Courses)
If you are starting to learn data structures and algorithms, jumping right into technical questions may be too difficult. Everyone gains understanding differently; this is where Udemy steps in to offer courses on how to approach solving questions through guided video solutions.
You may find that many data structure and algorithm questions and solutions are written in Java. While Java is used for learning statically typed and OOP languages, most bootcamps teach JavaScript. The web runs on JavaScript, so learning to solve problems in JavaScript makes the most sense. Luckily, one of the most popular Udemy data structures and algorithms courses uses JavaScript for all their examples. This course is The Coding Interview Bootcamp: Algorithms + Data Structures. It walks through the theory and multiple practical problems in a step-by-step, easy-to-follow manner.
While online courses are helpful to get you started, do not expect that taking a course will fully prepare you for a coding interview. Completing a course is only the beginning. To gain mastery of this topic, you will need to practice questions on the other platforms without the aid of an instructor.
Cracking the Coding Interview (Book)
The final resource we will discuss is a book, not an online platform or course. This is the go-to guide for gaining a deep understanding of data structures and algorithms in the context of FAANG company interviews. This book was written by a software engineer, Gayle Laakmann McDowell, who has interviewed for tech jobs, coached, and been the hiring manager for software engineers.
Along with offering sections detailing the different data structures or algorithms common to interviews, she also provides hints on diagnosing and discussing problems. One of the less stressed and practiced skills for technical interviews is the ability to explain what you are doing while you do it. Yes, you can solve the problem, but questions and answers are not black and white in the real world.
This fantastic resource covers soft-skill areas of data structures and algorithms that the other resources do not.
Find a Program that Excels at Data Structures and Algorithms
These resources are fantastic for continuing your data structures and algorithms education. Not everyone starts with a good base. You should check out a software engineering bootcamp if you are looking to enter tech and get a good foundation for writing scalable, efficient code. Thinkful offers a 5-week Software Engineering Bootcamp that covers Full Software Engineering concepts, including a section focused entirely on learning and mastering data structures and algorithms!