LeetCode Preparation and Interview Tips

Introduction

• Sharing personal experiences from solving 1500+ LeetCode problems and interviews at big tech companies like Amazon, Google, and Microsoft.
• Goal: To make others' LeetCode journey easier and more effective.

Why Use LeetCode?

• Necessary for interviews at big tech companies; smaller startups may not require it.
• LeetCode is a robust platform for interview preparation.

Choosing a Programming Language

• No specific language required; choose popular languages like C++, Java, Python, or JavaScript.
• For beginners, Python is recommended for its ease and simplicity.
• Stick to a language you know well if you're already familiar.

Importance of Data Structures and Algorithms

• Understanding CS fundamentals (time/space complexity, basic data structures).
• Learn Big O Notation to improve understanding and efficiency.
• Familiarize with arrays, strings, trees, linked lists, stacks, queues, hashmaps.
• Basic algorithms: sorting, searching, recursion.
• Recommended resources: William Fiset's YouTube channel, "Data Structures and Algorithms Made Easy," "Cracking the Coding Interview."

Problem Selection on LeetCode

• Solve by topic for deeper understanding; start with easy problems.
• Focus on medium-level problems for interviews.
• Curated problem lists: NeatCode 75, Top 100 Liked, Top Interview 150.
• Avoid highly disliked and demotivating questions.

Quantity of Problems to Solve

• Aim for 300-400 problems.
• Focus on understanding over quantity.
• Find the fun and challenge in solving problems.

Approaching New Problems

• Understand problem statement and expected inputs/outputs.
• Start with a brute-force solution, then optimize.
• Plan before coding; understand the approach.
• Test with small inputs and edge cases.

Handling Stuck Situations

• Spend 30-60 minutes on a problem before looking at solutions.
• Use hints and try implementing solutions independently.
• Mark difficult problems for revision.

Solving Problems Efficiently

• Identify patterns in problems to apply similar solutions.
• Practice pattern recognition.

Memorizing Solutions

• Avoid memorizing; focus on understanding.
• Understanding helps with problem-solving and explaining thought processes.

Practicing Like an Interview

• Practice in a timed environment using tools like LeetCode Timer and participate in contests.

LeetCode Premium

• Not necessary for beginners.
• Benefits: premium problems, company-specific problems, visual solutions.
• Alternatives: Free online resources, YouTube videos.

Conclusion

• Encouragement to share questions or video requests.
• Best wishes for the viewer's coding journey.