Grokking Data Structures & Algorithms for Coding Interviews

What it covers

The course page lists 17 chapters, 266 lessons, 273 playgrounds, 199 assessment questions and about 50 hours of study time (September 2026). It is text-based with runnable code in the browser.

The order is deliberate, each structure building on the last:

• Arrays and matrices
• Stacks and queues, including circular queues and deques
• Linked lists, singly and doubly linked
• Trees and binary search trees, traversal techniques and when to use BFS or DFS
• Hash tables (hashing, collisions, overflow and resizing) and hash sets
• Heaps
• Graphs, with representations, DFS and BFS
• Tries

Then four algorithm chapters: sorting, searching, greedy algorithms, and divide and conquer. A final chapter on choosing the right data structure includes a cheat sheet of structures, algorithms and costs, then a final exam.

Each structure chapter covers how it works, the built-in version in Python, Java, C++, JavaScript, Go and C#, practice problems with full solutions, a flashcard review and a chapter assessment. Complexity is stated for every solution, time and space separately.

Why this matters for interviews

Many failed coding interviews are not pattern failures. They are moments where a candidate reaches for a list when a heap was needed, or cannot explain why a hash lookup is constant time on average but not in the worst case. Interviewers probe exactly that, and grinding problems does not fix it if the foundations are shaky.

Is it worth it?

It is most useful if you learned to code through a bootcamp or tutorials and never took a formal data structures course: it fills that gap with practice built in. If you already know the structures, the chapter assessments are a quick way to confirm it before moving on to pattern practice.

As of September 2026 the course page lists a one-time price of $78 for lifetime access, and it is included in the provider's all-courses subscription. The page shows a 4.2 rating from about 9,800 ratings and roughly 29,500 learners.

Theory, problems, flashcards and assessments sit together in one ordered path, so there is no need to assemble material from different places.

How long it really takes

Fifty hours is the provider's estimate. At an hour a day that is roughly two months; at two hours a day, four to six weeks. Do not rush the hash table, heap and graph chapters; they carry most interview weight.

How to get the most from it

• Implement each structure yourself in your main language before reading the provided implementation. Building a heap once teaches more than reading five.
• Use the flashcards and assessments as a check, not a formality. Retake the ones you miss a few days later.
• Move on at the right time. Once you finish the graph and trie chapters, start Grokking the Coding Interview: Patterns for Coding Questions while doing the algorithm chapters alongside.

Common questions

Is it for complete beginners to programming? No. You need to be comfortable writing functions, loops and classes in one language.

Which language should I use? Whichever you will interview in. Python is the most common choice because it is short to write under time pressure.

Best for: students, career switchers and self-taught developers who need data structure foundations before pattern practice.