Why Google and Facebook Test You on Binary Trees During Interviews

During technical interviews at Google and Facebook, aspiring engineers often find themselves facing binary tree problems. This practice has several underlying reasons that contribute to the assessment of a candidate's capabilities. Understanding these reasons can provide valuable insight into what interviewers are looking for and how to excel in the tech industry.

Algorithmic Thinking

Binary trees serve as a fundamental data structure that helps assess a candidate's problem-solving and algorithmic thinking skills. Manipulating pointers or references, understanding traversal methods like in-order, pre-order, and post-order, all require a strong grasp of algorithms. This not only evaluates a candidate's technical skills but also their ability to think logically and methodically, crucial traits in the tech industry.

Complexity Analysis

Absent these tree problems in interviews, gauging a candidate's ability to analyze the time and space complexity of algorithms would be more challenging. Efficient code is paramount in software development, and binary tree problems provide a concrete way to measure this skill. By understanding and optimizing the complexity of tree-related algorithms, candidates demonstrate their proficiency in writing efficient, performant code.

Abstract Problem-Solving

Many real-world problems can be abstracted to trees or graphs. By testing candidates on binary trees, interviewers can gauge their ability to generalize problem-solving skills to other contexts. This abstraction allows the interview to assess a candidate's broader problem-solving capabilities, which are vital for tackling a wide range of challenges in the tech industry.

Standardized Evaluation

While binary trees may not be used directly in day-to-day coding, they provide a standardized framework for evaluating candidates. As a well-established part of coding interviews, these problems offer a common ground for objective comparison. Interviewers can easily compare candidates' knowledge and skills, making the assessment process more efficient and fair.

Preparation for Real Challenges

Even though binary trees might not be used directly in everyday coding tasks, the underlying concepts are relevant. Many systems and applications use tree structures, such as databases, file systems, and network routing. Understanding these tree-based constructs can significantly enhance a candidate's ability to grasp and effectively tackle more complex systems.

Conclusion

In summary, while binary trees may not be the most common data structure used in daily coding tasks, the skills and thought processes developed through solving such problems are invaluable in the tech industry. These interviews not only test a candidate's technical skills but also their problem-solving abilities and conceptual understanding.

Final Thoughts

The next time you face a binary tree problem during a tech interview at Google or Facebook, remember that these questions are designed to evaluate your overall capabilities. By mastering these concepts, you can stand out as a strong candidate and succeed in the competitive world of tech.