Electrical Engineer, Reality Labs

Meta

Let's explore some fundamental algorithms. Suppose you're given an unsorted array of integers. Describe how you would implement the following sorting algorithms: Bubble Sort Insertion Sort Merge Sort Quick Sort For each algorithm, explain: The basic principle behind the algorithm. The time complexity in the best, average, and worst-case scenarios. The space complexity. Whether the algorithm is stable or unstable. Provide example code snippets (in any language you prefer, but indicate which language you are using) demonstrating the core logic of each algorithm. Focus on clarity and conciseness in your code. Discuss the advantages and disadvantages of each sorting algorithm. When would you choose one algorithm over another, and why? For example, consider a scenario where you have a nearly sorted array. Which algorithm would perform best, and why? Imagine you're working with a very large dataset that doesn't fit into memory. Which sorting algorithm(s) could you adapt to handle this situation, and how would you do it? (Hint: Think about external sorting techniques). To illustrate, consider an array [5, 1, 4, 2, 8]. Show how each of the listed algorithms would sort this array step by step.

Meta

Design a System for Real-Time Twitter Trending Topics Let's design a system to identify trending topics on Twitter in real-time. Consider the following: Data Ingestion: How would you ingest the massive stream of tweets from Twitter? Processing: How would you process the tweets to extract relevant information (e.g., hashtags, keywords)? Trending Detection: How would you identify trending topics based on the processed data? What algorithms or techniques would you use? Scalability: How would you design the system to handle a large volume of tweets and users? Storage: What storage solutions would you use to store the tweets and trending topics? Consider both short-term and long-term storage. Network Requirements: Estimate the network bandwidth required for data ingestion and processing. Performance Optimization: How would you optimize the system for low latency and high throughput? For example, assume that Twitter generates 500 million tweets per day. Design a system that can identify trending topics within a few minutes, considering the computational resources, storage, and network bandwidth needed.

Meta

Could you describe a situation where you faced a significant memory leak issue in a C++ application and how you diagnosed and resolved it? Please walk me through the tools and techniques you used, the challenges you encountered, and the ultimate solution you implemented. For example, imagine you're working on a large-scale C++ application for processing high-volume financial transactions. The application is experiencing performance degradation over time, eventually leading to crashes. After initial investigation, you suspect a memory leak. Describe your approach to identifying the source of the leak. Consider discussing the specific tools you might employ, such as memory profilers (e.g., Valgrind, AddressSanitizer), debugging techniques (e.g., heap analysis), and code review strategies. What were some of the initial hypotheses you formed, and how did you validate or refute them? What were the key code areas you focused on based on your initial findings? Furthermore, explain any specific coding practices or patterns that contributed to the leak (e.g., improper use of smart pointers, forgetting to release dynamically allocated memory). How did you correct these issues, and what steps did you take to prevent similar leaks from occurring in the future? Did you implement any automated testing or monitoring to detect memory leaks early on? Finally, reflect on any lessons learned from this experience and how it has shaped your approach to memory management in C++.