How to Learn Data Structures and Algorithms?

Data structures and Algorithms (DSA) is a term most programmers/Computer science students approach with great dismay. Before moving on to the deeper concepts, it is important to go through the basic idea of DSA and the reason for its popularity these days.

What Are Data Structures & Algorithms?

We live in the Era of Big Data. An enormous amount of data is being generated from internet/social networks, traditional business systems, and increasingly from the Internet of Things. Humanity is facing countless challenges in processing, analyzing, and interacting with massive amounts of data in real time.

The question is, where do we store all this data so that we can fetch it when needed? Several tools like Hadoop, Apache Spark, etc. provide massive storage for any kind of data with substantial processing power. The base of all these tools is Data Structures and Algorithms.

Data Structures is all about structuring/storing data efficiently so that we can easily retrieve it and process it when needed, and Algorithms are certain methods to operate on this data.

We have algorithms to implement operations like insertion, deletion, updating, sorting, searching, etc. but to apply these algorithms initially data has to be structured properly.

To quote mathematically: Data Structures + Algorithms = Program

All operations starting from using abstract data types like list, stack, etc., to implementation of AI, need a prerequisite knowledge of Data Structure. DSA is also very helpful while learning any programming language.

Challenges In Learning DSA

DSA is actually a fabulous subject. Once you nail the concepts, it is fun to play with the numerous ideas in it. However, the difficulty in visualizing and understanding the concepts is a common problem faced by beginners.

We have a lot of resources available, but books have proven to be less interactive, and newbies find it difficult to conceptualize properly. The most challenging part of the process of learning DSA is to convert the theory portion taught to code format.

There are numerous resources available online that can help you in achieving this goal, which will be mentioned in the latter portion of this article.

Mastering the concepts of DSA can help you in taking your competitive programming to the next level and also crack interviews of big/small companies.

So learning such an important subject demands commitment, hard work, and constant practice too.

How To Learn DSA?

The entire process of learning DSA can be broken down into mainly three steps:

1. Basics Of Data Structures

The basic concepts of DSA include arrays, linked lists, stacks, and queues in linear structures, while trees, graphs, heaps, etc., in hierarchical structures.

At first, get familiar with these terms and their underlying concepts. Try implementing a tree/linked list and storing data in it. Also, practice measuring the time and memory consumed by an algorithm and data structure.

Every data structure has its own functionality, and once you reach an expert level, you will know which data structure to use for a particular program.

2. Patterns

Now since you know how to create a data structure, let’s move on to patterns. Patterns are some key algorithms related to a data structure. Start doing operations on the created data structure, be it an array, stack, linked list, or any other data structure of the kind.

Try implementing several algorithms like swapping, splitting linked lists, etc. While dealing with patterns, understand the theoretical concept of the algorithm, try visualizing it, and then practice implementing it.

3. Compound Algorithms

Once you are done with patterns, don’t settle. It’s time for us to move on to compound algorithms.

Compound algorithms involve combinations of algorithms and more than one pattern. Most of the interview questions related to DSA usually arise from this section. It’s almost like a puzzle, an opportunity to combine several algorithms and patterns creatively. It deals with problems like reversing a link list and then iterating it, etc.

Resources To Learn DSA

Let’s look at some of the resources to learn data structures and algorithms.

MyCodeSchool

MyCodeSchool is a YouTube channel. They provide a playlist containing about 100 videos of DSA. This will be a good resource for beginners since they start from scratch, and they use C language mainly to implement DSA concepts. They do provide English subtitles, and the graphics quality used is also really good.

Stanford Courses From Coursera

Tim Roughgarden’s course on DSA is one of the highly recommended options. Here you can practice and master the basics of algorithms and data structures through numerous types of assessments.

With the help of several multiple-choice quizzes and weekly programming assignments available here, learning DSA is made efficient. You can go through these courses on your own schedule. Roughgarden’s funfilled idiomatic presentations will help to learn turn fun.

Udacity’s Intro To DSA Course

The Intro to Data Structures and Algorithms course is python based. More than theoretical aspects, here they focus mainly on practical problems based on algorithms.

I would say this course will be useful for interview level preparations too. You can opt for this course to go through the frequently asked technical interview questions and learn how to structure your responses.

GeeksForGeeks

GeeksForGeeks is mostly known for its tech blog, and most students use it along with their academics to ace the concepts easily. It can be used as a code dictionary. I would suggest it for learning the theoretical concepts, which are explained precisely in the simple language here.

Once you pick up these concepts, jump to other platforms where you can practice problems to sharpen your programming skills.

Udemy’s Easy to Advanced Data Structures

Easy To Advanced Data Structures is a free course provided by Udemy to learn the concepts of DSA from the basic level to the advanced level. It is java based. Prior knowledge in java would make this course easier.

A lot of students opt for this medium since it is a complete tool in learning DSA.

It also has a course from an interview perspective related to DSA. Click here to check it out.

Algorithms & Data Structures Course In EdX

EdX and UCSanDiegoX provide a very good course to understand algorithmic techniques and apply them to solve real-life computational problems as well as algorithmic problems. Click here to check it out.

This course is a good mix of theory and practice. There are multiple tests for each algorithm you develop to ensure its correctness and run-time efficiency.

These are some of the prominent resources available online that can help you in mastering DSA. Which one to be used depends on your skillsets and preference.

I would say, check out some of these and go with the one you feel comfortable and please keep in mind that your choice might not be the one suiting your friend. It depends on the person.

Final Thoughts

Whatever be the resource, it is your practice, patience, and hard work that determines your success rate.

Once you understand the DSA concepts, I’m pretty sure you’re gonna nail down a variety of interviews, and move on to the next levels of your programming career. So, keep learning.

If you have any doubts, feel free to put them in the comments section. I’ll be happy to respond.