Product Quality Engineer, Network Hardware

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You are given a list of integers. Modify the list in-place such that all even numbers appear at the beginning of the list and all odd numbers appear at the end. The relative order of even numbers and odd numbers does not matter. For example: If the input list is [3, 1, 2, 4, 6, 7], a valid output would be [2, 4, 6, 3, 1, 7]. Another valid output would be [4, 2, 6, 1, 3, 7]. The even numbers (2, 4, 6) are at the beginning, and the odd numbers (3, 1, 7) are at the end. If the input list is [1, 3, 5, 7], the output should be [1, 3, 5, 7] since all numbers are already odd. If the input list is [2, 4, 6, 8], the output should be [2, 4, 6, 8] since all numbers are already even. If the input list is [], the output should be []. Write a function that takes a list of integers as input and modifies it in-place to satisfy these conditions. Your solution should be efficient, ideally completing the modification in O(n) time complexity and O(1) space complexity.

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Let's design a stories feature, similar to Instagram or WhatsApp. These stories should disappear after a friend views them and only be available for 24 hours after publishing. Consider the following aspects: Functionality: How would users create and upload stories (photos and videos)? How would users view stories from their friends? How would you implement the 24-hour expiration? How would you handle the disappearing aspect after viewing? Scalability: How would you handle a large number of users uploading and viewing stories simultaneously? How would you efficiently store and retrieve stories? How would you manage the storage as stories expire? Data Model: What database schema would you use to store story information (user, timestamp, media URL, view status)? How would you track which users have viewed a story? Technical Challenges: What are the potential challenges in implementing this feature? How would you address issues like latency, storage limitations, and data consistency? Edge Cases: How would you handle users with slow internet connections? What happens if a user uploads a story right before the 24-hour mark? How would you handle deleted user accounts and their associated stories?

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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++.