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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
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 511–540 of 1706 results
- DoorDashMediumSoftware EngineerSimulate Constant-Time Random Courier Selection
Design a courier pool data structure that supports adding, removing, and uniformly selecting random courier IDs in average O(1) time.
Coding & AlgorithmsTechnical ScreenData StructuresHash TableArray - DoorDashMediumSoftware EngineerSolve BFS grid delivery routing
This question evaluates proficiency in grid-based graph traversal and shortest-path computation, along with complexity analysis and handling dynamic changes, assessing skills in algorithm design, graph algorithms, and data structures within the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - DoorDashMediumSoftware EngineerSolve string match and DashMart BFS
This question evaluates proficiency with string algorithms and pattern matching, assessing understanding of substring search complexity and algorithm selection within the algorithms and data structures domain, and is commonly asked to verify efficient low-level text-search implementation and time/space trade-off reasoning at a practical implementation level. The "Dash Mart" grid BFS evaluates graph traversal, state-space modeling, and shortest-path reasoning for multi-target collection tasks within graph algorithms and path-finding, and is commonly asked to measure competence in BFS-based search, state encoding and optimization strategies with a focus on practical algorithmic application and performance considerations.
Coding & AlgorithmsTechnical Screen - DoorDashMediumSoftware EngineerValidate a Shopping Cart
Implement a shopping cart validation function that checks item availability, consolidates duplicate entries, verifies inventory levels, and ensures order minimums are satisfied.
Coding & AlgorithmsTechnical ScreenHash TableData ValidationBusiness Logic - DropboxMediumData ScientistCompute max island with constrained flips
This question evaluates understanding of grid-based graph connectivity, connected-component labeling, and algorithmic complexity analysis (time and space) within the Coding & Algorithms domain, emphasizing practical algorithm design for large-scale inputs.
Coding & AlgorithmsTechnical Screen - DuolingoEasySoftware EngineerImplement String Encryption and Decryption
This problem tests your ability to manage character mapping and reverse lookups using dictionaries to perform basic string transformation and reconstruction.
Coding & AlgorithmsTechnical ScreenStringsDictionariesHash Maps - EightfoldaiMediumSoftware EngineerMake a Parentheses String Valid
This question evaluates proficiency in string manipulation and delimiter matching, specifically balancing parentheses while preserving character order and handling edge cases.
Coding & AlgorithmsTechnical Screen - ElasticMediumSoftware EngineerImplement log aggregation in React
This question evaluates a candidate's front-end development and real-time data-aggregation skills, specifically React component state management, handling streaming updates, choosing appropriate in-memory data structures (e.g., Map), and timestamp parsing/comparison for per-category frequency and last-update tracking.
Coding & AlgorithmsTechnical Screen - EnigmaMediumSoftware EngineerSearch Book Titles
This question evaluates proficiency in string processing, tokenization, case-insensitive matching, anagram detection, and algorithmic design for efficient search and deduplication.
Coding & AlgorithmsTechnical Screen - EricssonMediumSoftware EngineerSolve Triangle Rows and Top Frequencies
This question set evaluates understanding of combinatorial number patterns and frequency-based selection, specifically the ability to generate an additive number triangle and to identify the k most frequent elements, assessing skills in array/list manipulation, counting, and selection algorithms.
Coding & AlgorithmsTechnical Screen - EtsyMediumData ScientistImplement streaming autocomplete under tight memory
This question evaluates a candidate's ability to design a memory- and latency-constrained autocomplete service, testing skills in data structure selection, string/Unicode normalization, approximate string matching, concurrency, dynamic updates, and algorithmic time/space analysis.
Coding & AlgorithmsTechnical Screen - ExoduspointMediumSoftware EngineerFind minimal time for four people crossing
This question evaluates algorithmic problem-solving and combinatorial optimization skills, focusing on reasoning about constrained pairing, state-space search, and minimizing total time under movement constraints.
Coding & AlgorithmsTechnical Screen - ExpediaHardSoftware EngineerMaximum Sum Skyline
This problem tests your ability to optimize search spaces and use stack-based structures to maintain monotonic properties under specific geometric constraints.
Coding & AlgorithmsTechnical ScreenDynamic ProgrammingData StructuresOptimization - ExpediaHardSoftware EngineerSolve three interview coding problems
This multi-part question evaluates string manipulation, combinatorial counting, and constrained enumeration skills through sequence generation, palindromic-anagram substring counting, and wildcard digit-sum completion tasks.
Coding & AlgorithmsTechnical Screen - ExperianMediumData ScientistDesign Algorithm for Longest Increasing Subsequence Length
This question evaluates algorithm design and data structure skills, covering subsequence analysis, constraint/graph modeling for seating, and external-memory sorting considerations for scalability.
Coding & AlgorithmsTechnical Screen - FaireMediumSoftware EngineerFind first 5-7-5 haiku in sentence
Find first 5-7-5 haiku in sentence 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 & AlgorithmsTechnical Screen - FaireMediumSoftware EngineerPrint a Centered Pascal Triangle
This question evaluates the ability to generate combinatorial structures (Pascal's triangle) and apply precise numeric formatting, alignment, and string-layout skills, reflecting algorithmic thinking and attention to presentation details.
Coding & AlgorithmsTechnical Screen - FanaticsMediumSoftware EngineerPlot ASCII chart for time-price pairs
This question evaluates skills in array manipulation, coordinate mapping, and ASCII-based data visualization, focusing on transforming unsorted time-price pairs into a fixed 2D grid and handling point collisions and empty cells.
Coding & AlgorithmsTechnical Screen - FigmaMediumSoftware EngineerCheck Graph Reachability For File Permissions
Practice graph reachability for simplified file-permission inheritance under directed, undirected, and blocked-edge variants. The prompt is useful for reviewing DFS or BFS, visited sets, cycle handling, and clarifying traversal semantics.
Coding & AlgorithmsTechnical Screen - FigmaMediumSoftware EngineerDesign document layer with undo/redo
This question evaluates a candidate's understanding of reversible state mutation and undo/redo semantics, covering batching, inverse operation representation, operation compression, failure handling, and choice of data structures for edit history.
Coding & AlgorithmsTechnical Screen - FigmaMediumData EngineerWrite SQL for first share and closest collaborator
This question evaluates SQL proficiency—specifically joins, filtering, type casting, temporal aggregation, window functions or deduplication, and deterministic tie-breaking—by requiring derivation of first non-creator view times and per-creator collaborator counts from event tables.
Coding & AlgorithmsTechnical Screen - FlexportMediumSoftware EngineerSolve Two Robbery Optimization Variants
This problem tests your ability to apply dynamic programming to linear structures and tree-based data structures to find the maximum weight independent set under constraints.
Coding & AlgorithmsTechnical ScreenDynamic ProgrammingTreesRecursion - FlexportMediumSoftware EngineerValidate and restore IPv4 addresses
This question evaluates string processing, strict input validation rules, and constrained combinatorial search skills (e.g., backtracking) for generating and verifying IPv4 addresses.
Coding & AlgorithmsTechnical Screen - FlipsterEasySoftware EngineerCompute max profit from one stock trade
This question evaluates a candidate's understanding of array-based data processing, difference maximization, and basic algorithmic optimization for time-series inputs. It is commonly asked in Coding & Algorithms interviews to assess fundamental practical programming ability and attention to edge cases (e.g.
Coding & AlgorithmsTechnical Screen - Fora TravelMediumSoftware EngineerMerge Two Unsorted Arrays into the First Array
Tests array manipulation, handling buffer capacity without relying on placeholder values, and analyzing the trade-offs of in-place sorting strategies.
Coding & AlgorithmsTechnical ScreenArraysSortingIn-Place - FortinetMediumSoftware EngineerSolve linked list reversal and minima problems
This problem tests your ability to manipulate linked list pointers iteratively and perform efficient binary search on a structurally complex matrix.
Coding & AlgorithmsTechnical ScreenLinked ListPointersBinary Search - Fuse EnergyMediumSoftware EngineerImplement simplified Excel with SET/GET/SUM
This question evaluates understanding of data structures and algorithms for modeling and implementing a simplified spreadsheet, covering dependency graphs, formula evaluation, incremental updates, and cycle detection.
Coding & AlgorithmsTechnical Screen - Garner HealthMediumSoftware EngineerValidate a String of Brackets
This problem tests the candidate's ability to use a stack data structure to track nested states and handle character matching logic.
Coding & AlgorithmsTechnical ScreenStackStringsData Structures - GeMediumSoftware EngineerCount visible people to the right
This question evaluates algorithmic problem-solving with arrays and visibility relations, assessing competency in array traversal, handling of relative ordering constraints, and designing time- and space-efficient approaches.
Coding & AlgorithmsTechnical Screen - GeneralmotorsHardMachine Learning EngineerCount Islands in a Grid
This problem tests your ability to navigate a 2D grid and identify distinct connected components using graph traversal techniques like Depth-First Search (DFS) or Breadth-First Search (BFS).
Coding & AlgorithmsTechnical ScreenGraphsDFSBFS
DoorDash
Dropbox
Expedia
Experian
Faire
Figma