Senior Software Engineer, Security and Privacy, Pixel Phone

Google

Given n pairs of parentheses, what is the total number of different, valid combinations of those parenthesis? For example: For n = 1, the only valid combination is (), so the answer is 1. For n = 2, the valid combinations are ()() and (()), so the answer is 2. For n = 3, the valid combinations are ((())), (()()), (())(), ()(()), and ()()(), so the answer is 5. Calculate the number of valid parenthesis combinations for a given n. Explain the formula or method used to arrive at the answer. What is the underlying mathematical concept at play here, and how does it ensure that we only count valid combinations, avoiding invalid ones such as )()(? Detail the relationship between this problem and Catalan numbers, and discuss how this relationship can be utilized to efficiently compute the number of valid combinations, even for relatively large values of n.

Google

Let's design a cache. Consider the following requirements: Basic Functionality: Implement a cache with put(key, value) and get(key) methods. Eviction Policy: Implement an LRU (Least Recently Used) eviction policy. When the cache is full, the least recently accessed item should be evicted to make space for the new item. Thread Safety: Ensure the cache is thread-safe to handle concurrent access from multiple threads. Generics: The cache should be able to store any type of key and value (using generics). Time Complexity: get and put operations should have an average time complexity of O(1). Example Usage: Cache cache = new Cache(5); // Cache with capacity 5 cache.put(1, one); cache.put(2, two); cache.get(1); // Access key 1, moves it to the most recently used cache.put(3, three); cache.put(4, four); cache.put(5, five); cache.put(6, six); // This will evict key 2 (LRU) System.out.println(cache.get(2)); // Output: null (because it was evicted) Discuss the data structures you would use, the implementation details for each method, and how you would address thread safety.

Google

Let's discuss your skillset. To start, can you elaborate on your technical proficiencies, such as your experience with programming languages, frameworks, and tools? For instance, have you worked with Python, Java, or C++? Are you familiar with front-end frameworks like React or Angular, or back-end technologies like Node.js or Django? Can you provide examples of projects where you effectively utilized these skills to overcome technical challenges? Furthermore, how do you approach learning new technologies and integrating them into your existing workflow? In addition to technical skills, can you share examples of your soft skills, such as communication, teamwork, problem-solving, and leadership? For example, describe a situation where you effectively communicated a complex technical concept to a non-technical audience, or a time when you successfully collaborated with a team to achieve a common goal. How do you handle conflicts within a team, and what strategies do you employ to ensure that everyone's voice is heard? Finally, how do you stay up-to-date with the latest industry trends and advancements, and how do you continuously develop your skills to remain competitive in the ever-evolving tech landscape?