Coding Test Preparation, For Those Just Starting Out: Which Platform is Best?

(Shocking Statistics) Every year, the biggest challenge for developers preparing for coding interviews is a lack of ‘problem-solving ability’ and a sense of being overwhelmed by ‘which platform to use?’ Despite LeetCode’s dominance, in Korea, coding test preparation takes many different forms. Recent hiring announcement analysis revealed that Baekjoon and Programmers still hold a significant portion of the weight in actual coding interviews. It's crucial to focus on choosing a platform that’s most suitable for you, rather than simply following the latest trends.

Baekjoon, Programmers, and LeetCode – Navigating the Three Major Barriers

Coding test preparation platforms shouldn’t just offer problem-solving spaces; they should provide an environment to improve problem-solving skills, understand algorithms, and develop practical experience. Each platform has its own strengths and weaknesses, and your learning stage and goals should dictate your usage strategy.

1. Baekjoon Online Judge: ‘Build a Solid Foundation’ – A Reliable Classic Style

• Difficulty Classification (S-B): S (Very Easy – Easy), A (Medium), B (Hard)
• Features: Baekjoon is a platform with a long history, and is most suitable for improving basic algorithmic problem-solving skills. It boasts extremely detailed solution explanations, allowing you to follow the problem-solving process step by step. It provides the opportunity to practice solving problems 'on your own' without seeing the answer, which is particularly beneficial.
• Advantages: Huge number of problems, detailed explanations, active participation from the Korean developer community.
• Disadvantages: Fewer problems reflecting the latest technology trends compared to LeetCode or Programmers.
• Personal Experience: When I first prepared for coding tests, I consistently solved Baekjoon’s easier problems to increase my understanding of basic algorithms. In particular, the 'Nth Number' problem, which required a simple algorithm to solve without complex logic, helped me gain confidence. Recently, I frequently encounter problems that mirror Baekjoon's problem style in startup coding tests.

2. Programmers: ‘Cultivating Practical Experience’ – A Practical Learning Platform

• Difficulty Classification (S-B): S (Very Easy – Easy), A (Medium), B (Hard)
• Features: Programmers, like Baekjoon, offers a variety of algorithmic problems, but many are similar to problems frequently seen in actual corporate coding tests. The solution explanations are more concise than Baekjoon's, but clearly present the core solution methods.
• Advantages: Preparation for real coding test problems, a wide range of topics, and a ranking system that motivates competitive spirit.
• Disadvantages: The explanations are somewhat brief, which can lead to a lack of understanding of the problem-solving process.
• Practical Application: Frequently tested ‘Stack Queue’ problems on Programmers are helpful in increasing understanding of commonly used data structures in web development. Recently, companies are increasingly conducting coding tests based on Programmers’ rankings.

3. LeetCode: ‘Following Global Trends’ – A Global Platform

• Difficulty Classification (S-B): S (Very Easy – Easy), A (Medium), B (Hard)
• Features: LeetCode is the most widely used coding test platform globally. It provides problems that reflect the latest technology trends and requires a deep understanding of various algorithms and data structures.
• Advantages: Reflects latest technology trends, huge number of problems, global community, diverse problem types (greedy, dynamic programming, graph, etc.).
• Disadvantages: Higher difficulty and requires a lot of time and effort to solve problems. You need to be proficient in using English.
• Practical Experience: The experience gained through LeetCode is greatly helpful in solving problems frequently appearing in large-scale corporate coding tests. Increasingly, global IT companies like Facebook and Google are using LeetCode to conduct coding interviews.

Tier Classification and Learning Strategy

• S Tier: Start with Baekjoon's easy problems and build a solid understanding of basic algorithms.
• A Tier: Solve intermediate-level problems on Baekjoon and Programmers, improving problem-solving abilities.
• B Tier: Solve intermediate-level problems on LeetCode, learning about the latest technology trends and cultivating practical experience.

Practical Tips

• Consistency: Coding test preparation is not something you can finish in a short period. You need to consistently solve problems to improve your skills.
• Use an Error Log: Record the problems you get wrong in an error log and analyze why you made them to try solving them again.
• Utilize the Community: Participate in online communities to share information and ask questions with other developers.
• Mock Coding Tests: Conduct mock coding tests in an environment similar to a real coding test to gain practical experience.

Conclusion

Coding test preparation isn't just about improving problem-solving skills; it's about developing problem-solving ability, understanding algorithms, and cultivating practical experience. Baekjoon, Programmers, and LeetCode each have unique strengths, and you should use them appropriately based on your learning stage and goals. We hope you can successfully pass the coding test through persistent efforts and grow into a fantastic developer in the field you want to pursue.