Welcome to my collection of Leetcode solutions! Here you'll find my approaches and solutions to various Leetcode problems in different programming languages.
- 🚀 Leetcode Solutions
- 🛠️ Problem-Solving Approach
- 🧠 Understand the Problem
- 📝 Break down the problem and brainstorm solutions
- 🧩 Identify the Problem Type
- 🛠️ Choose the Right Data Structures
- ✍️ Draft a Direct Solution (Pseudocode)
- ⚡ Optimize the Solution
- 🧪 Test with Pseudocode
- 🧑💻 Implement the Solution in Code
- 🔧 Refactor for Clarity
- ✅ Submit and Review
- 📘 Learn and Practice
- 🔄 Iterate and Improve
- 🧠 Understand the Problem
- 📝 Note
- 💻 Solutions
A structured approach is crucial for efficiently tackling LeetCode problems and developing strong problem-solving skills. This process emphasizes critical thinking and understanding over simply finding a working solution.
💡 I utilize the Pomodoro Technique to maintain focus and prevent burnout during problem-solving sessions. This involves working in focused 25-minute intervals, followed by 5-minute breaks. Resources: Forest or Pomofocus
Here's my step-by-step approach:
-
- Read the problem statement carefully, multiple times if necessary. If you're having difficulty with English, you might consider using DeepL translator, a way better alternative than Google translator.
- Re-read the statement, highlighting key concepts, constraints, and requirements. Clearly identify the inputs and desired outputs.
- You can use the snipping tool (Windows) or any other alternatives for Mac/Linux to capture any relevant information.
- Simplify and break down complex problems into smaller, more manageable subproblems. Divide and conquer!
- A good way of knowing if you truly understand the problem is imaging that you are teaching somebody else the problems with your own words.
-
- Study and analyze the provided examples to fully understand the expected behavior and create additional test cases if needed, including edge cases (e.g., empty inputs, maximum values) to deepen your understanding of the problem.
- Sketch a flowchart or other diagram type to visualize the input-output flow if necessary. These are some useful tools you may include for this taks:
- Draw.io
- Lucidchart
- Figma
- AlgoMonster - A highly useful tool not just for creating flowcharts, but also for understanding the best data structures, algorithms, and other problem-solving techniques.
-
- Categorize the problem: Is it related to search, sorting, optimization, graph traversal, or another common type?
- Identify applicable patterns or techniques: Sliding window, divide and conquer, backtracking, two pointers, dynamic programming, etc.
-
- Select the most suitable data structures for the problem:
- Arrays, hash maps, heaps, trees, graphs, etc.
- Evaluate the time and space complexities for any scenario needed (Big O).
- This is a usefull resource for deciding wich data structure, pattern or algorithm should you use.
Credit to: https://www.softwaretestinghelp.com/data-structures-in-cpp/ - Select the most suitable data structures for the problem:
-
- Develop a straightforward, initial solution using pseudocode. This serves as a baseline and helps identify potential bottlenecks and find beter solutions later.
- Estimate the time and space complexity of this initial approach.
-
- Explore ways to enhance the algorithm's efficiency:
- Can a different data structure reduce complexity?
- Can redundant computations be eliminated?
- Compare alternative approaches and select the most efficient one based on time and space complexity.
- Explore ways to enhance the algorithm's efficiency:
-
- Validate the optimized solution using test cases on paper or in pseudocode.
- Ensure it handles all edge cases correctly.
-
- Translate the pseudocode into your preferred programming language. Leetcode allows you to use a vast variety of programming languages such as: C++, Java, Pyhton, C, C#, JavaScript, TypeScript, PHP, Swift, Kotlin, Dart, Go, Ruby, Scala, Rust, Racket, Erlang and Elixir.
- Ensure the code is clean, modular, and follows best practices.
-
- Simplify complex logic and improve code readability.
- Add comments to explain key sections of the code.
-
- Submit the solution on Leetcode and create the markdown. It will help to clarify what you've done.
- Review and analyze high-rated solutions: Don't just check if your solution works – actively learn from others! Analyze high-rated solutions to identify alternative approaches, optimizations, and best practices.
-
- Study better solutions, focusing on techniques or optimizations you may have missed.
- Reimplement those solutions to solidify your understanding.
-
- If you discover new insights or patterns, revisit and refine your solution.
- Keep iterating until you're confident it's the best possible approach. Improvement takes time—sometimes months or even years. After submitting your solution, always review others' approaches to learn from them and apply these lessons to this and to future problems. There's no shame in studying someone else's solution; Don’t skip this step, it is a key part of the learning process.
If you're feeling stuck or frustrated during the process, consider taking a longer break or continuing the next day. Sometimes, giving your mind some rest leads to better solutions. Don't forget to stay active with regular exercise, and make sure you're getting enough sleep and proper nutrition and hydration. Believe it or not this will help you solve problems more effectively.
By following this systematic process, I ensure that my solutions are not only correct but also efficient and well-documented. Here is a valuable resource of a similar procedure: Link
Below is a list of Leetcode problems that I have solved. Each entry includes a link to the problem, my solution, and its difficulty level.