Blind 75 Practice List

What the list is

The Blind 75 became one of the most widely used interview practice lists because it is short enough to finish and broad enough to cover the problem types that appear most often. This version organises the 75 problems into five topic areas:

• Sequences (12 problems): arrays and strings, including sliding window and two pointers
• Data structures (11 problems): linked lists, hash maps and sets
• Non-linear data structures (13 problems): trees and graphs
• More data structures (15 problems): heaps, stacks, queues and tries
• Dynamic programming (10 problems): optimal substructure and sequence problems

Each problem is labelled easy, medium or hard and has a link to practise it and a link to a detailed solution.

Features that help you practise

• Step-by-step solutions that explain the approach, not just the code
• Hints for the harder problems, so you can get unstuck without reading the full answer
• An integrated coding workspace to write and test code in the browser
• Progress tracking to mark problems as solved and see how far you have come
• Notes to record insights and mistakes for each problem

The emphasis is on quality over quantity: a small set of high-impact problems rather than hundreds of random ones.

How to use it well

1. Work topic by topic, in the order listed, rather than jumping around. Each area builds on the previous one.
2. Give each problem a real attempt, around 30 to 40 minutes, before opening a hint.
3. Use the hint before the solution. A hint that gets you moving teaches more than a full answer.
4. Write notes after every problem: the key idea, the pattern it used and any mistake you made.
5. Put anything you could not solve on a revision list and retry it a week later from scratch.
6. Say your reasoning aloud as you solve, as you would in an interview.

How long it takes

At two problems a day, the list takes about five to six weeks, including revision. Spending an hour or two a day is realistic for students alongside classes. Faster is possible if you already know the fundamentals well.

Where it fits in a preparation plan

The list works well as a structured core or as a checkpoint partway through preparation. Problems you cannot start point precisely to topics you need to revisit. For deeper pattern practice, the Coding Interview Playbook learning path and the pattern-organised Problem Set in this library build on the same foundations, and the Company Interview Guides help you tailor the final weeks to a specific employer.

Common questions

Is it free? Yes. The list, solutions and practice tools are free to use.

Is it enough on its own? It covers the most common problem types. Revising your weak topics and practising aloud turn it into interview readiness.

Which language can I use? Any language you are comfortable with; the workspace supports common interview languages.

Best for: students and engineers who want a focused, well-known set of problems to structure their practice or check their readiness.