How Long Does It Take to Master LeetCode Medium Questions?

The path to becoming proficient at LeetCode medium-level questions varies significantly among individuals, depending on factors such as prior programming experience, familiarity with algorithms and data structures, and the amount of time dedicated to practice.

Factors Influencing Proficiency

Several key factors contribute to one's proficiency with LeetCode medium problems:

1. Prior Programming Experience

If you already possess a strong foundation in programming and algorithms, gaining confidence in medium problems could take as little as a few weeks to a couple of months. However, for beginners, it may take several months to a year to feel comfortable with these problems.

2. Practice Frequency

Regular practice is crucial. Many users find that solving 1-2 medium questions daily can lead to significant improvement over time. Consistent practice helps reinforce concepts and build problem-solving skills.

3. Learning Approach

Actively reviewing and understanding the solutions to problems you find challenging can expedite your learning journey. Engaging with the community, discussing problems, and supplementing your knowledge with external resources can also be beneficial.

4. Goal Setting

Setting specific goals, such as solving a certain number of problems per week, can help maintain motivation and track your progress. Regularly setting short-term goals can ensure steady improvement and sustainable learning.

Personal Progress and Experience

Having solved over 300 LeetCode questions, including around 100 easy, 170 medium, and 30 hard questions, one can reflect on the journey to gaining proficiency in medium-level questions.

In the initial stage, even easy questions might seem challenging. However, as you accumulate more practice, solving problems becomes progressively easier. The process is often a spiral: solving 60 to 70 easy problems might take about a month, after which one transitions to medium questions.

Some medium questions are indeed difficult, but these problems also serve as opportunities to learn and apply concepts like Dynamic Programming (DP), Backtracking, and Recursion. These topics might be challenging, but they are fundamental to conquering medium problems. It generally takes around 3 months to become fairly comfortable with medium-level questions.

Gradually, you can try tackling hard problems, but solving these entirely on your own can be quite different. It requires a deep understanding and extensive practice.

Key Topics for Medium-Level Problems

To become good at medium-level LeetCode problems, several critical topics need to be mastered:

1. Simple Graph Algorithms

Breadth-First Search (BFS) Depth-First Search (DFS)

Understanding these algorithms is essential for many problems, especially those involving graphs.

2. Union-Find Data Structure

Mastering this data structure is crucial for problems that require efficient union and find operations, such as connected components in a graph.

3. Map and Set Data Structures

Knowing how to implement and use maps or dictionaries and sets can greatly enhance problem-solving efficiency.

4. Dynamic Programming (DP)

Potential problems might involve complex algorithms such as matrix chain multiplication, which exemplifies the application of DP.

5. Linked Lists

Many medium-level problems involve linked lists, so familiarity with operations on them is indispensable.

6. Sliding Window Technique

This technique is widely used in medium and even some hard problems, making it a valuable skill to master.

7. Recursion and Backtracking

Understanding and practicing these techniques is crucial, even though you may not have encountered them yet in your journey on LeetCode.

8. Sorting and Binary Search

These are fundamental to many easy and medium-level problems, so having a solid grasp of them is beneficial.

9. Priority Queues (Heaps)

Understanding the use of priority queues as min or max heaps can be helpful for solving certain problems efficiently.

Estimating the Time to Proficiency

If you are just starting to learn programming, expect it to take about 3 to 4 months to gain proficiency with medium-level questions. This journey, while challenging, is rewarding, and with consistent practice and the right approach, you will undoubtedly improve.

Remember, becoming proficient in LeetCode medium questions is not just about solving problems quickly; it's about deepening your understanding and building a robust problem-solving skill set. Continuous learning and practice will set you on the right path.