algorithm Interview Questions
12 interview questions in our bank cover algorithm, most of them Coding & Leetcode-style Questions. They average 3.2/5 difficulty — medium — and each one was reported by a candidate after a real interview. Companies known to ask about algorithm: OpenAI, Mobile, Google, LinkedIn, CrowdStrike, and 1 more.
Practice these on the problems board →Companies that ask about algorithm
Question mix
- Coding & Leetcode-style Questions9
- Mobile Engineering (Android/iOS)3
Difficulty
- 3/5 — medium10
- 4/5 — hard2
Questions tagged algorithm
Data Labeling Task Scheduler
3/5Designed around a complex scheduling scenario reported at OpenAI, this coding task requires building a fair allocation engine for multi-party workflows involving models, humans, and specific tasks. You will implement robust distribution logic that satisfies strict quota limits, workload balancing thresholds, and uniqueness constraints across various participation phases. This problem thoroughly tests advanced greedy allocation, state management, and constraint satisfaction techniques. Access to the full problem text and complete model solution requires a subscription.
Coding & Leetcode-style QuestionsOpenAIMemory Allocator
4/5Featured in OpenAI interview rounds, this systems programming problem requires engineering an efficient memory allocation and deallocation manager. Candidates must avoid naive linear scans and design a data structure that handles fixed-capacity resource allocation and release operations with optimal time complexity. The task tests deep understanding of memory management algorithms, pointer arithmetic, and data structure selection for performance-critical applications. Reviewing the full problem requirements and complete model solution necessitates a subscription.
Coding & Leetcode-style QuestionsOpenAIIP Address / CIDR Iterator
3/5Design a robust network address iterator capable of parsing IP ranges and CIDR blocks while supporting bi-directional traversal and membership checks, featured in interviews at OpenAI. The problem unfolds incrementally through multiple implementation stages, testing your ability to handle boundary conditions, numerical conversions, and iterator protocols cleanly. It evaluates your knack for writing modular, self-consistent code that scales with evolving requirements. Read the full multi-part problem description and examine the clean solution code with a subscription.
Coding & Leetcode-style QuestionsOpenAIShard Rebalance / Overlapping Key Range
3/5Solve a distributed systems puzzle focusing on dynamic range allocation and shard rebalancing, highlighted in recent engineering interviews at OpenAI. Your task involves maintaining a collection of keyed intervals, handling insertions and deletions, and executing a rebalance routine to cap maximum overlaps while minimizing data movement. This problem challenges your algorithmic thinking regarding interval sorting, gap filling, and efficient resource partitioning. Access the full problem details and expert solution architecture by subscribing today.
Coding & Leetcode-style QuestionsOpenAIRanked-Choice Voting (Instant Runoff)
3/5Simulate a preferential voting system frequently discussed in engineering interviews at LinkedIn. This algorithmic challenge involves tracking multi-round ballot preferences, systematically eliminating underperforming candidates, and redistributing votes until a clear majority emerges. The exercise examines your ability to manage complex state transitions, handle tie-breaking edge cases, and write robust simulation code. Review the complete specification, structural requirements, and optimized source code by obtaining a full subscription.
Coding & Leetcode-style QuestionsLinkedInGate Entry / Exit Time Resolution with Tie-Break Rules
3/5In this reported Google interview question, candidates must process a sequence of entry and exit requests for individuals passing through a controlled gate. The challenge focuses on determining the precise clearance timestamp for each person when multiple events overlap, requiring careful handling of simultaneous actions and priority rules. This problem evaluates your ability to simulate state transitions and apply deterministic tie-breaking logic. Access to the complete problem description and an optimal model solution requires a subscription.
Coding & Leetcode-style QuestionsGoogleShuffle a Deck of 52 Cards
3/5Practice a classic randomization challenge reported during interviews at CrowdStrike, which asks you to fairly rearrange a standard collection of unique elements. The core task is to build a uniform permutation approach where every possible arrangement has an identical chance of occurring. This exercise evaluates your grasp of randomized algorithms, efficiency, and statistical fairness. Access the complete breakdown, complexity analysis, and verified model implementation through a paid subscription.
Coding & Leetcode-style QuestionsCrowdStrikeIdentify Bad Nodes in Network
4/5In this technical challenge reported from Alibaba, you must isolate faulty components within a distributed network using batch testing procedures. Given a set of elements and a verification oracle that flags the presence of any compromised unit, the goal is to categorize every node accurately while optimizing query efficiency under strict concurrency limits. This puzzle evaluates advanced algorithmic design, divide-and-conquer strategies, and resource management. Access to the full problem description, complexity analysis, and optimal solution requires a subscription.
Coding & Leetcode-style QuestionsAlibabaLRU Cache for an Image Memory Cache
3/5This mobile engineering interview question focuses on designing a fixed-capacity least-recently-used cache, a core component utilized in modern application memory management and bitmap loading libraries. Candidates must implement a data structure supporting efficient retrieval and insertion operations while automatically evicting stale items based on access history. The task tests your understanding of underlying pointer manipulations and time-complexity trade-offs. Subscribe today to unlock the complete problem requirements, detailed explanation, and production-ready model implementation.
Mobile Engineering (Android/iOS)MobileDebounce a Search-Box Keystroke Stream
3/5Master a classic client-side engineering problem frequently encountered in mobile development roles by implementing a trailing-edge debounce mechanism for an interactive search keystroke stream. The objective is to process a chronological list of input timestamps and determine the exact moments network triggers should fire after user typing pauses for a designated interval. This exercise evaluates your understanding of asynchronous event handling, stream transformations, and timing logic essential for responsive application design. Secure full access to the comprehensive problem explanation and code solution with a subscription.
Mobile Engineering (Android/iOS)MobileMerge Overlapping Analytics Sessions
3/5When processing usage telemetry on mobile clients, overlapping time intervals frequently need consolidation before syncing to the backend. This popular interview challenge reported by Mobile tests your ability to efficiently manage and combine continuous temporal ranges in linear or logarithmic time. You will need to handle unsorted inputs and correctly identify touching or intersecting boundaries. Access to the complete problem description and expert reference solution requires a subscription.
Mobile Engineering (Android/iOS)MobilePath Minimizing the Maximum Cell (Swim in Rising Water)
3/5This Google technical interview question challenges you to navigate a grid while minimizing the highest individual cost encountered along the journey from the origin to the destination. Rather than summing cumulative weights, the goal is to optimize the worst-case hurdle on the chosen path, testing your proficiency with priority queues, graph traversal, and modified shortest-path algorithms. A related follow-up extends these concepts to general weighted network routing scenarios. Dive into the complete problem analysis and expert-written code solution with a subscription.
Coding & Leetcode-style QuestionsGoogle
Studied alongside
algorithm interview FAQ
- How many algorithm interview questions are there?
- 12 reported questions, mostly Coding & Leetcode-style Questions.
- Which companies ask algorithm questions?
- OpenAI (4), Mobile (3), Google (2), LinkedIn (1), CrowdStrike (1), Alibaba (1).
- How hard are algorithm questions?
- They average 3.2 out of 5: 10 at 3/5, 2 at 4/5.