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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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- 11
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- 8
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Showing 721–750 of 3276 results
- Capital OneMediumSoftware EngineerSort Every Concentric Matrix Border Clockwise
This problem tests array traversal, boundary management, and sorting logic by requiring you to isolate concentric layers of a matrix and sort their contents independently.
Coding & AlgorithmsOnline AssessmentArraysSortingMatrix - Capital OneMediumSoftware EngineerSort Matrix Diagonals By Their Values
Tests matrix traversal along anti-diagonals, string formation, and custom multi-key sorting with deterministic tie-breaking.
Coding & AlgorithmsTechnical Screenmatrixsortingstrings - Capital OneMediumSoftware EngineerSorted Sums of Absolute Differences Over All Cyclic Shifts of an Array
Given two integer arrays of equal length, compute the sum of absolute differences between the second array and every cyclic rotation of the first, then return all of these sums in non-descending order. It tests rotation index arithmetic, accumulation over every shift, and exact output ordering.
Coding & AlgorithmsOnline Assessment - Capital OneHardSoftware EngineerSum of Distinct Values on the Borders of All Maximum-Sum Square Frames
Among all square frames of a given size inside an integer matrix, find those with the largest border sum, then add up the distinct values that appear on the borders of every such frame. Tests careful border enumeration that excludes interior cells, tie handling across several frames, and de-duplication by value.
Coding & AlgorithmsOnline Assessment - Capital OneHardMachine Learning EngineerSupport updates and count target-sum pairs
This problem tests the ability to maintain frequency counts of elements in a dynamic dataset and perform efficient range-sum queries for pairs that satisfy a target condition.
Coding & AlgorithmsOnline AssessmentHash MapData StructuresFrequency Array - Capital OneMediumSoftware EngineerTop Two Teams by Points, Then Goal Difference, Then Goals Scored
Given parallel arrays of wins, draws, goals scored and goals conceded for each team, compute points as three per win plus one per draw and return the indices of the top two teams. Ties are broken by goal difference, then goals scored, then index, testing multi-key comparison and careful tie handling.
Coding & AlgorithmsHR Screen - 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 - CargurusMediumData ScientistReverse a Character Array In Place
This problem tests the ability to manipulate array elements in-place using two-pointer logic while adhering to strict space complexity constraints.
Coding & AlgorithmsTechnical ScreenArraysTwo PointersIn-place - 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 - CerebrasMediumSoftware EngineerImplement Binary Search in C++
This question evaluates proficiency in implementing binary search in C++, focusing on iterative control flow, correct handling of not-found cases, boundary conditions, and understanding of algorithmic correctness.
Coding & AlgorithmsTechnical Screen - CerebrasMediumSoftware EngineerImplement and Optimize Vector Multiplication
This question evaluates a candidate's ability to implement vector–vector multiplication and to reason about performance optimizations and sparse data structures, assessing competencies in algorithm design, parallel computing, memory hierarchy, and numerical operations.
Coding & AlgorithmsTechnical Screen - ChalkMediumSoftware EngineerCompute rainwater accumulation on a height grid
Tests the ability to simulate 2D fluid accumulation using priority-queue-based graph traversal (similar to Dijkstra's algorithm) to track spilling boundaries.
Coding & AlgorithmsTechnical Screenheapbfsgraph - Character.AIMediumSoftware EngineerFind Shortest Covering Substring
This problem tests your ability to use the sliding window technique and hash maps to find the smallest window in a string that contains all characters of a target pattern.
Coding & AlgorithmsTechnical ScreenSliding WindowHash MapTwo Pointers - ChariotMediumSoftware EngineerExplore an HTTP Maze
This question evaluates the ability to integrate HTTP-based APIs with graph traversal and state management, covering concepts such as breadth-first exploration for shallow-first search, cycle avoidance, transient error handling, and key-lock resource constraints.
Coding & AlgorithmsTechnical Screen - Chicago Trading CompanyMediumSoftware EngineerBuild an Ordered Latest-Quote Container
Build an insertion-ordered container that stores only the latest quote for each stock symbol. Support expected O(1) push, pop, and size operations while updating bid and ask values without changing a symbol's original position and safely rejecting malformed commands.
Coding & AlgorithmsTechnical Screen - Chicago Trading CompanyMediumSoftware EngineerImplement a Constant-Time Simple Moving Average
Implement a fixed-window simple moving average with O(1) processing for every valid add and query. Maintain a rolling sum and bounded queue, average the samples available before the window fills, and return deterministic results for empty, malformed, or unknown operations.
Coding & AlgorithmsTechnical Screen - Chicago Trading CompanyEasySoftware EngineerMerge Nested Dictionaries Iteratively
This question evaluates a candidate's skill in iterative data structure manipulation and handling of nested dictionary merging semantics, including conflict resolution and value overriding.
Coding & AlgorithmsOnline Assessment - ChimeMediumSoftware EngineerImplement single-tab browser history navigation
This question evaluates understanding of data structures, stateful API behavior, amortized time complexity, set membership tracking, and edge-case handling for implementing browser-like history navigation in the coding & algorithms domain.
Coding & AlgorithmsTechnical Screen - 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 - ChimeMediumBackend EngineerSolve classic backend coding problems
This problem tests your ability to handle string manipulation, recursion with backtracking, and mapping logic by generating all valid word combinations from a numeric keypad sequence.
Coding & AlgorithmsTechnical ScreenBacktrackingRecursionStrings - CircleHardSoftware EngineerImplement Recipe Storage CRUD
This question evaluates the ability to design and implement in-memory data structures and APIs for CRUD operations, covering skills such as ID generation and parsing, string handling for case-insensitive uniqueness constraints, data modeling, and preserving original value casing.
Coding & AlgorithmsTechnical Screen - CircleMediumSoftware EngineerImplement a simplified multi-level banking system
Implement a simplified multi-level banking system 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 & AlgorithmsOnline Assessment - CircleMediumSoftware EngineerImplement cheapest itinerary with date filters
This question evaluates proficiency in graph algorithms and constrained pathfinding, including handling date filters for initial departures, time-ordered connections, cycle avoidance, and quantitative complexity analysis.
Coding & AlgorithmsOnline Assessment - CiscoHardSoftware EngineerImplement an LFU Cache
This problem tests your ability to design a data structure that supports O(1) insertions and lookups while managing cache eviction based on access frequency and recency.
Coding & AlgorithmsTechnical ScreenHash TableLinked ListDesign - CiscoEasySoftware EngineerLongest Substring Without Repeated Characters
This problem tests string manipulation, hash map usage, and the sliding window technique to find a specific substring based on unique character constraints.
Coding & AlgorithmsTechnical ScreenSliding WindowStringsHash Map - CiscoMediumSoftware EngineerSolve max-subarray, min-unique, and grid-jump
This question evaluates array algorithms and algorithmic problem-solving skills, specifically contiguous-sum optimization (greedy/DP reasoning), frequency counting and memory-constrained selection for unique minima, and grid traversal simulation with boundary and visit-state management.
Coding & AlgorithmsOnline Assessment - CitadelMediumSoftware EngineerCompute BBO and NBBO from order data
This question evaluates a candidate's skill in designing efficient data structures and algorithms for aggregating and querying order-book data, including computing best bid/ask prices and summing quantities at those prices.
Coding & AlgorithmsTechnical Screen - 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 EngineerCompute max team size with a core interval
This question evaluates algorithmic problem-solving around interval overlap and time-complexity optimization, measuring the ability to determine the maximum team size given a core interval while reasoning about interval intersections and scalability; it is commonly asked to assess correctness and subquadratic runtime thinking, categorized under Coding & Algorithms and emphasizing practical algorithmic implementation. The follow-up evaluates combinatorics and counting under adjacency constraints with modular arithmetic and efficient handling of large parameters, commonly posed to test recurrence reasoning and scalable counting approaches, falling under combinatorics/dynamic programming and emphasizing conceptual understanding linked to practical algorithmic efficiency.
Coding & AlgorithmsOnline Assessment - CitadelMediumSoftware EngineerCompute maximum later-earlier difference
This problem tests your ability to optimize an O(n^2) brute-force search into an O(n) linear-time solution using a single-pass scan while maintaining state variables.
Coding & AlgorithmsOnline AssessmentArraysOptimizationGreedy
Capital One
Cerebras
Chime
Circle
Citadel