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Coding & Algorithms Interview Questions
Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.
- 9403
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- 546
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Showing 211–240 of 1080 results
- C3 AIHardData ScientistFind the Intersection of Two Linked Chains
This problem tests the ability to detect the intersection point of two singly linked lists with constant space complexity, focusing on pointer manipulation and list traversal techniques.
Coding & AlgorithmsOnsiteLinked ListsTwo PointersAlgorithms - Capital OneMediumData ScientistAutomate Python Virtual Environment Setup on Linux Terminal
This question evaluates proficiency in shell scripting and Linux terminal automation for Python virtual-environment setup, focusing on environment management, automation, and reproducibility skills relevant to data science workflows.
Coding & AlgorithmsOnsite - Capital OneMediumSoftware EngineerBuild a Banking System with Activity Rankings
This problem tests your ability to design a system that maintains account state and dynamically updates an ordered leaderboard of account activity using efficient data structures.
Coding & AlgorithmsOnsiteHash MapBalanced BSTDesign - Capital OneMediumData ScientistDebug and test a Python function in venv
This question evaluates understanding of Python runtime semantics (mutable default arguments, in-place list mutation during iteration), debugging and unit-testing practices, virtual environment and packaging workflows, and CI/tooling considerations.
Coding & AlgorithmsOnsite - Capital OneMediumSoftware EngineerImplement deposit, withdraw, and transfer in a class
This question evaluates a candidate's competence in concurrent programming, atomic state updates, and class-level account management for basic monetary operations.
Coding & AlgorithmsOnsite - Capital OneMediumData ScientistOptimize invites under capacity constraints
This question evaluates a candidate's competency in probabilistic expected-value optimization, algorithmic efficiency for large-scale inputs, and constrained combinatorial selection including grouped all-or-nothing decisions and cost modeling.
Coding & AlgorithmsOnsite - Capital OneMediumSoftware EngineerPlace Pieces on a Grid
This question evaluates spatial reasoning, matrix and array manipulation, collision detection, and stateful simulation skills required to implement ordered placement of shaped pieces on a grid.
Coding & AlgorithmsOnsite - Capital OneMediumData ScientistRefactor code and enforce robustness
This question evaluates proficiency in code refactoring, robustness, input validation, unit testing, environment specification, and complexity analysis for Python data-processing workflows (pandas), within the Coding & Algorithms domain for Data Scientist roles.
Coding & AlgorithmsOnsite - Capital OneMediumMachine Learning EngineerReturn all root-to-leaf tree paths
This question evaluates competence with binary tree structures, path enumeration and traversal techniques along with the ability to represent traversal results as formatted strings.
Coding & AlgorithmsOnsite - Capital OneEasyData ScientistReview Preprocessing Code and Tests
This problem tests your ability to identify common pitfalls in data science pipelines, specifically concerning data leakage, handling missing values, and software engineering best practices for reproducibility.
Coding & AlgorithmsOnsiteData PreprocessingData LeakageCode Review - Capital OneMediumData ScientistValidate Unit-Test Coverage and Identify Missing Scenarios
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Validate Unit-Test Coverage and Identify Missing Scenarios states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsOnsite - CarvanaEasySoftware EngineerSpell Out a Nonnegative Integer
This question evaluates a candidate's ability to decompose integers and implement precise string-formatting logic, including mapping numeric values to their English word equivalents and managing scale units and boundary conditions.
Coding & AlgorithmsOnsite - ChimeMediumSoftware EngineerSimulate toppling board game outcome
This question evaluates a candidate's ability to implement a discrete board-game simulation, including state management, turn-based ownership semantics, stack-based piece handling, capture mechanics, and game termination detection.
Coding & AlgorithmsOnsite - CitadelMediumSoftware EngineerCompute Every Fixed-Size Submatrix Sum
Compute every contiguous fixed-size submatrix sum without mutating the input, using a padded two-dimensional prefix grid to answer each window in constant time.
Coding & AlgorithmsOnsite - CitadelMediumSoftware EngineerDesign dynamic weighted random sampling with updates
This question evaluates a candidate's ability to design and analyze dynamic data structures that support weighted random sampling with inserts and deletes, testing skills in algorithm design, complexity analysis, and randomized sampling under large numeric constraints.
Coding & AlgorithmsOnsite - CitadelMediumSoftware EngineerGenerate Prefix-Based Product Suggestions
Generate up to three lexicographically smallest product suggestions for every prefix of a search word, with efficient handling once a prefix has no matches.
Coding & AlgorithmsOnsite - CitadelMediumSoftware EngineerImplement array merge, round-robin scheduler, and trading simulator
This problem tests your ability to manipulate data structures efficiently, implement a fair process scheduler, and manage event-driven state transitions.
Coding & AlgorithmsOnsiteArraysQueuesHeaps - CitadelMediumSoftware EngineerImplement task queue with insert, delete, execute
This question evaluates a candidate's ability to design and implement efficient dynamic priority management, including priority ordering, insertion-order tie-breaking, and support for add, remove, and execute operations.
Coding & AlgorithmsOnsite - CitadelMediumSoftware EngineerPerform an External Merge Sort with a Heap
Implement an external merge sort simulation that partitions a data stream into memory-bounded sorted runs and merges them using a min-heap.
Coding & AlgorithmsOnsiteExternal SortHeapStreaming - CitadelMediumSoftware EngineerSimulate 2048 and pack board into uint64
This question evaluates proficiency in implementing deterministic game-state logic and compact binary representations, specifically array manipulation and merge semantics for 2048 slide operations plus bit-level packing/unpacking of 4-bit exponent fields.
Coding & AlgorithmsOnsite - CitadelHardData ScientistSort a nearly sorted array
This question evaluates algorithmic problem-solving skills, specifically understanding sorting under constrained inputs and rigorous time and space complexity analysis.
Coding & AlgorithmsOnsite - CitiMediumSoftware EngineerExplain data structure fundamentals
This question evaluates understanding of data structure fundamentals, specifically hash map internals (hashing, collision resolution strategies, load factor, and resizing), time complexity analysis for search/insert/delete, contrasts between arrays and linked lists for random access and insertion, and typical use cases and complexities for stacks versus queues. It is commonly asked in technical interviews to assess algorithmic thinking and the ability to reason about performance trade-offs and appropriate data structure selection; domain: Coding & Algorithms; level: tests both conceptual understanding and practical application.
Coding & AlgorithmsOnsite - ClickupMediumSoftware EngineerProcess document edit events
This question evaluates implementing and manipulating a line-based document through sequential event processing, emphasizing array/list operations, string handling, and state management; it belongs to the Coding & Algorithms domain and tests data-structure and input-event processing competency.
Coding & AlgorithmsOnsite - CloudflareMediumSoftware EngineerImplement a rule-based rate limiter
Design and implement a multi-rule rate limiter that tracks client request quotas across matching path prefixes using a sliding time window.
Coding & AlgorithmsOnsitesliding-windowdata-structuresdesign - Cockroach LabsMediumSoftware EngineerPoint-in-Time Reads from a Timestamped Key-Value Store
Build a versioned key-value store whose reads return the value a key held at a given timestamp: the latest write at or before that time, or an empty string if there is none. Tests choosing a per-key data layout that keeps point-in-time lookups fast across up to 200,000 operations.
Coding & AlgorithmsOnsite - CohereMediumSoftware EngineerDelete One '5' From a Digit String to Get the Largest Number
Given a digit string containing at least one 5, delete exactly one 5 so the remaining string has the largest possible numeric value, keeping any leading zeros. This intern online-assessment problem tests reasoning about how each digit position affects a number and careful handling of repeated digits.
Coding & AlgorithmsOnsite - CohereMediumMachine Learning EngineerImplement Autoregressive Decoding Strategies
This problem tests your ability to implement common sequence decoding strategies used in large language models by manipulating token probability distributions.
Coding & AlgorithmsOnsiteLLMSamplingSoftmax - CoinbaseMediumSoftware EngineerAnalyze food-delivery data
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Analyze food-delivery data states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsOnsite - CoinbaseMediumSoftware EngineerCompute Total Manual Distance
This problem tests your ability to simulate a state-based movement process and calculate cumulative distance based on a non-monotonic set of instructions.
Coding & AlgorithmsOnsiteArraysSimulationMath - CoinbaseMediumSoftware EngineerDesign order stream with state transitions
Design order stream with state transitions evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsOnsite
C3 AI
Capital One
Chime
Citadel
Citi
Cloudflare
Cohere
Coinbase