What is a good revision strategy for coding interview problems?

Preparing for coding interviews can be a challenging process, and it's quite common to feel like you're forgetting older problems as you learn new ones. The key to effective revision is to ensure that you're not just passively reviewing material but actively engaging with it. Here's a comprehensive approach to revising coding problems effectively that will help you retain and reinforce your understanding of the problems you've already worked on:

1. Categorize Problems

• Organize by Topic: Group the problems you've solved by topics such as arrays, strings, linked lists, trees, graphs, dynamic programming, etc. You can also group question by coding patterns. This helps in focusing your revision on specific data structures or algorithms.
• Difficulty Level: Note the difficulty level of each problem (easy, medium, hard). This can help in pacing your revision sessions according to your confidence level in each topic.

2. Active Recall and Spaced Repetition

• Active Recall: Test yourself on a problem without looking at the solution. Try to recall the problem statement, your approach, and the solution. Active recall strengthens memory retention.
• Spaced Repetition: Revisit problems after varying intervals. Use longer intervals each time a problem is correctly recalled. This technique is proven to enhance memory and understanding over time.

3. Understand, Don’t Memorize

• Focus on understanding the underlying principles and logic behind each solution rather than memorizing code. Being able to derive solutions from first principles is key in interviews.

4. Analyze Your Mistakes

• Keep a log of common mistakes or misconceptions you encounter. Review this log regularly to avoid repeating the same errors and to reinforce correct practices.

5. Practice Writing Code on Paper

• Coding in an interview often means writing code by hand or on a whiteboard. Practice this to get comfortable with syntax without relying on an IDE's autocomplete and syntax highlighting features.

6. Mock Interviews

• Regularly schedule mock interviews with peers or use platforms like Pramp or DesignGurus.io. Simulate real interview conditions to practice articulating your thought process and coding under time constraints.

7. Teach What You’ve Learned

• Explain solved problems to someone else or write about them. Teaching is a powerful tool for reinforcing your own understanding and spotting gaps in your knowledge.

8. Review Solutions and Discussions

• After attempting a problem, review the official solution and community discussions. Pay attention to alternative approaches and the trade-offs between different solutions.

9. Set Aside Time for Regular Review Sessions

• Dedicate specific times in your study schedule for revision, separate from your time spent on solving new problems. Regular, short review sessions can be more effective than infrequent, long sessions.

10. Use Flashcards

• Create flashcards for key algorithms, data structure operations, time complexities, and problem-solving patterns. Review these flashcards regularly as part of your spaced repetition strategy.

11. Maintain a Problem Journal

• Keep a journal of problems you've solved, including notes on the approach, alternative solutions, and any insights or tips. This journal can be a quick reference guide during your revision sessions.

12. Stay Healthy

• Ensure you're getting enough sleep, exercise, and nutrition. Your brain needs to be in top condition to retain information and perform well during interviews.

Conclusion

A good revision strategy for coding interview problems involves organized review sessions, understanding concepts over memorization, active recall, spaced repetition, and regular practice under interview-like conditions. By following these strategies, you can enhance your problem-solving skills, retain information better, and perform more confidently in coding interviews.