Apple Intern Interview Detailed explanation of interview details|Two rounds of pure coding Apple interviews

1,958 Views

This year, Apple Intern interviews have been sent out in large numbers, but I still noticed that some students didn’t even receive an OA. In my personal judgment, this is very likely a resume issue. As is widely known, each big tech company has different resume preferences—if you didn’t get picked up, the first thing to check is whether your projects align with the company’s style.

Apple Intern Interview Experience

OOD

We want to design a parking lot system using an object-oriented approach. This parking lot is not just a single level—it has multiple levels. Each level is further divided into rows of parking spots. The parking lot should be able to accommodate different types of vehicles, such as motorcycles, cars, and buses. The system should support two core functionalities: Being able to locate where a vehicle is parked (which level and which spot). Automatically calculating the parking fee when a vehicle leaves.

Approach: The parking lot system consists of the following core classes:

  1. Vehicle (base vehicle class): defines common vehicle attributes
  2. Motorcycle, Car, Bus (concrete vehicle classes): inherit from Vehicle
  3. ParkingSpot (parking spot): stores information about an individual parking spot
  4. Level (floor/level): manages the parking spots on each level
  5. ParkingGarage (parking lot): overall management of the entire parking facility

Code

Problem: Given a[0]…a[N-1], find i <= j such that a[i] = a[j], and the subarray sum a[i] + … + a[j] is maximized.

这题看着像“找相同值的两端”,但核心其实是:固定右端 j 时,想让 sum(i..j) 最大,就要让 prefix[i] 尽量小(因为 sum = prefix[j+1] – prefix[i]),并且 a[i] 必须等于 a[j]。所以我会做两件事,先用前缀和 pref[k] = a[0]+…+a[k-1],对每个值 v,维护一个“目前为止出现过 v 的位置里,最小的 pref[i](以及对应下标 i),

When I scan to some j (with value v): I first use the current pref[j] to update the minimum prefix for v (this also covers the case i = j), then compute the candidate answer: pref[j+1] - minPref[v]. I update the global maximum and record i and j at the same time.

Solution

Data structure: HashMap(value -> (minPrefix, minIndex)) minPrefix: the minimum pref[i] achievable when this value is used as the left endpoint minIndex: the corresponding i, used to return the final interval.

Time complexity: O(N) (one pass through the array, with a HashMap operation at each step) Space complexity: O(U) (where U is the number of distinct values)

Follow-up 1: What if we require i < j (single-element subarrays are not allowed)?

It’s simple: when updating the answer, add a check that i < j; or change the timing of initializing/updating min_pref to “compute the candidate first, then put j into the map,” ensuring the left endpoint is always before the right endpoint.

Follow-up 2: What if we need to return “all intervals that achieve the maximum sum,” or apply a tie-break (e.g., if sums are equal, choose the shortest / earliest)?

tie-break 规则写进更新逻辑:和相同:比较长度 (j – i),还相同:比较 i 更小,如果要返回所有区间:需要在 map 里保留“同样最小 pref 的多个 i”(但一般面试不会真让你返回全部,更多是考你怎么定义 tie-break)。

Coding + Fundamentals (CS Basics)

For Apple Intern interviews, in addition to coding, sometimes they test fundamentals + coding together. The fundamentals are mainly around operating systems, such as the volatile keyword in C, how virtual memory works, and the principles behind deadlocks.

Code: Implement a hash table that supports insertion, lookup, and deletion. This type of interviewer has a common trait: they like to micro-manage—for example, halfway through your implementation they may give you a hint and tell you not to do it one way but another (even though there’s often no real difference). We should go along with the interviewer; otherwise, they may start to “battle” you and view your approach through a confrontational lens. It’s human nature, but we want to avoid that hassle.

BQ:Out of your comfort zone, tight deadlines, unable to meet your commitment — how would you communicate with the customer?

Preparation Summary

If you’re also preparing for Apple Intern or other big tech OA / VO interviews, you can directly contact programhelp to learn about the corresponding interview assistance and end-to-end coaching support. If you’d like me to assist with mock interviews, or practice using the original questions from Apple Intern interview experiences and get the most realistic feedback, feel free to reach out.

The only platform online that supports L6+ system design mock interviews, using real interview experiences only.

Job search assistance is ultimately a competition of time and quality. Consult Programhelp to get the most professional tech career coaching and interview support.

author avatar
Jack Xu MLE | Microsoft Artificial Intelligence Technician
Ph.D. From Princeton University. He lives overseas and has worked in many major companies such as Google and Apple. The deep learning NLP direction has multiple SCI papers, and the machine learning direction has a Github Thousand Star⭐️ project.
END
 0