Packaging Substrate Engineer

Apple

Given a string expression of numbers and operators, return all possible results from computing all the different possible ways to group numbers and operators. You may return the answer in any order. The test cases are generated such that the output values fit in a 32-bit integer and the number of different results does not exceed 104. For example: If the input is expression = 2-1-1 The expected output is [0,2] Because: ((2-1)-1) = 0 (2-(1-1)) = 2 If the input is expression = 23-45 The expected output is [-34,-14,-10,-10,10] Because: (2(3-(45))) = -34 ((23)-(45)) = -14 ((2(3-4))5) = -10 (2((3-4)5)) = -10 (((23)-4)5) = 10 Constraints: 1 <= expression.length <= 20 expression consists of digits and the operator '+', '-', and '*'. All the integer values in the input expression are in the range [0, 99]. The integer values in the input expression do not have a leading '-' or '+' denoting the sign.

Apple

Let's delve into the fascinating world of computer systems. I'd like you to design a simplified operating system. Assume you're building this OS for a resource-constrained embedded system, like a smart thermostat or a simple microcontroller-based device. Your design should address the following key aspects: Memory Management: Describe your approach to memory allocation and deallocation. How would you prevent memory leaks and fragmentation in this environment? Would you use static allocation, dynamic allocation, or a combination of both? Explain your reasoning, giving specific examples of how your chosen methods would work in practice. Process/Task Scheduling: How would you schedule tasks to run on the processor? Would you opt for a preemptive or non-preemptive scheduler? What scheduling algorithm (e.g., Round Robin, Priority-based) would you use, and why? Consider the trade-offs between responsiveness, fairness, and overhead. Imagine you have three tasks: Task A (high priority, short bursts), Task B (medium priority, longer computation), and Task C (low priority, background task). How would your scheduler handle these tasks? Interrupt Handling: Explain how your OS would handle interrupts from hardware devices (e.g., a temperature sensor, a button press). How would you ensure that interrupt handlers are efficient and don't disrupt the normal operation of the system? Describe the steps involved in processing an interrupt, from the moment it occurs to the point where the interrupted task resumes execution. File System (Optional): If your embedded system requires persistent storage, outline a simple file system design. How would you organize files and directories? What data structures would you use to track file metadata (e.g., name, size, location)? How would you handle file creation, deletion, and reading/writing operations? Assume the storage medium is a small flash memory chip with limited write cycles. Inter-Process Communication (IPC): How would different tasks or processes communicate with each other within your OS? Would you use message queues, shared memory, or another mechanism? Explain the advantages and disadvantages of your chosen approach. For example, consider a scenario where one task needs to send sensor data to another task for processing. How would you implement this communication? Remember to justify your design choices based on the constraints of the embedded system, such as limited memory, processing power, and energy consumption. Aim for simplicity, efficiency, and reliability in your design. Your explanation should demonstrate a solid understanding of operating system principles and their practical application in a real-world scenario.

Apple

Let's explore your motivations and understanding of Apple as a company. This role requires a deep commitment and genuine enthusiasm for our products and values. To start, I'd like to understand your perspective. Why are you interested in working at Apple, specifically?** What aspects of our company culture, products, or mission resonate with you? Can you provide specific examples that demonstrate your understanding of Apple's ecosystem and how it differentiates itself from competitors? Perhaps you can discuss how Apple's approach to innovation aligns with your own professional values and career goals? Furthermore, if you were to join our team, what unique contributions do you believe you could make to Apple's continued success? I'm looking for more than just a generic answer about wanting a job. I want to hear about a real connection to Apple and a clear vision for your potential role within the company. Think about our commitment to user experience, our focus on privacy, and our history of groundbreaking innovation. How do these factors influence your desire to be a part of Apple?