Is 300 LeetCode questions enough?

Completing 300 LeetCode questions can be a great way to prepare for coding interviews, but whether it's "enough" depends on factors such as the difficulty of the problems you solve, the variety of problem types, and how thoroughly you understand the concepts behind each problem. Here’s how to gauge if 300 LeetCode questions will be sufficient:

Factors to Consider:

1. Variety of Problem Types:

   • Coding interviews, especially at top tech companies like Meta, Google, or Amazon, typically cover a wide range of topics, including arrays, strings, dynamic programming, trees, graphs, recursion, backtracking, and more. If your 300 questions cover a broad spectrum of these topics, then it's likely you'll be better prepared.
   • Focus on mastering common coding patterns such as sliding window, two pointers, dynamic programming, and divide and conquer, as these frequently appear in interviews.

2. Difficulty of Problems:

   • It's essential to solve problems of varying difficulty levels—easy, medium, and hard. Many coding interviews will focus on medium to hard questions, so ensuring that a significant portion of your 300 questions fall into these categories is important.
   • Meta and other top-tier companies are known for medium to hard-level problems, so practicing these is crucial.

3. Understanding vs. Memorization:

   • It’s not just about the number of questions, but how well you understand the underlying concepts. If you're solving problems just to increase your count but not fully grasping the patterns or optimizations, 300 questions may not be as beneficial.
   • Make sure to review solutions, learn optimal approaches, and understand why certain algorithms work better for particular problem types.

4. Mock Interviews and Real-Time Problem Solving:

   • In addition to solving 300 LeetCode questions, practicing mock interviews can help you simulate real interview pressure. Sites like Pramp, DesignGurus.io, or even doing mock interviews with friends can help you gauge if you're ready.
   • Solving problems within the constraints of a timed environment will help you prepare better for real-world interview situations.

General Consensus:

• Quality over Quantity: Solving 300 well-rounded, diverse problems with a deep understanding is usually more effective than solving a higher number without truly grasping the solutions. Many candidates report success after solving fewer than 300 questions, while others might need more.

Additional Preparation Tips:

• System Design: If you're applying for a senior position, you'll also need to focus on system design concepts, which are typically not covered in LeetCode.
• Behavioral Interviews: Don’t neglect behavioral interviews. Tech companies place importance on cultural fit and values, so be prepared with examples of past experiences that showcase your problem-solving and teamwork abilities.

Conclusion:

300 LeetCode questions can definitely be enough if you focus on the right topics, balance difficulties, and ensure a solid understanding of key concepts. However, the quality of your preparation and the depth of your understanding matter more than the sheer number of questions solved.

Sources:

• LeetCode Discuss: Is 300 Enough?
• Blind Community Interview Experiences