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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
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- 11
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- 8
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Showing 661–690 of 1706 results
- HarveyMediumSoftware EngineerDesign a constrained in-memory file system
This question evaluates design and implementation skills for hierarchical in-memory data structures, string parsing and file-name collision handling under constraints, and the ability to reason about time and space complexity.
Coding & AlgorithmsTechnical Screen - HarveyHardSoftware EngineerDesign an In-Memory Spreadsheet Engine
Design an in-memory spreadsheet engine that supports cell updates, formula evaluations, cycle detection, and O(1) value lookups via proactive cache propagation.
Coding & AlgorithmsTechnical ScreenGraphTopological SortSystem Design - HarveyMediumSoftware EngineerDesign an in-memory file system with limits
This question evaluates the ability to design and implement hierarchical in-memory data structures, manage capacity constraints and OS-style duplicate naming, and reason about edge cases and time/space complexity.
Coding & AlgorithmsTechnical Screen - HarveyMediumSoftware EngineerEager Spreadsheet Formulas with Constant-Time Reads
Implement eager spreadsheet formulas with constant-time cached reads, transitive dependency updates, cycle rejection, and atomic definition replacement.
Coding & AlgorithmsTechnical Screen - HarveyMediumSoftware EngineerHandle multi-source string matching and tagging
This question evaluates skills in string matching, pattern recognition, overlap handling, text annotation, and counting occurrences across multiple source strings.
Coding & AlgorithmsTechnical Screen - HarveyHardSoftware EngineerImplement Spreadsheet Cell Updates
This problem tests your ability to manage a directed graph of dependencies and implement a topological update mechanism to recompute spreadsheet cell values efficiently.
Coding & AlgorithmsTechnical ScreenGraphDependency ManagementTopological Sort - HarveyMediumMachine Learning EngineerImplement a Spreadsheet With Formulas
This problem tests your ability to model cell dependencies using a directed graph, handle topological sorting for re-evaluation, and identify circular references.
Coding & AlgorithmsTechnical ScreenGraphsRecursionDFS - HarveyMediumSoftware EngineerImplement an Integer Spreadsheet with Formulas
Design an in-memory integer spreadsheet supporting cell assignments, additive formulas with nested references, and dynamic recalculation of acyclic dependency chains.
Coding & AlgorithmsTechnical ScreenDesignGraphDFS - HarveyMediumSoftware EngineerSpreadsheet Formula Engine with Cycle Detection
Design an in-memory spreadsheet formula engine supporting cell assignments, formula evaluation with dependencies, and cycle detection. The question tests directed graph modeling, topological invalidation, and cycle detection algorithms.
Coding & AlgorithmsTechnical Screengraphcycle-detectiontopological-sort - HeadwayMediumSoftware EngineerDebug and extend obstacle-run statistics classes
This question evaluates object-oriented design, debugging, algorithmic reasoning, and probabilistic simulation competencies by requiring fixes to class behavior, implementation of aggregate statistics, and a Monte Carlo-based probability estimator.
Coding & AlgorithmsTechnical Screen - HeadwayMediumSoftware EngineerGenerate Every Letter String a Phone Keypad Digit Sequence Can Spell
Given a string of digits from 2 to 9, return every letter string those digits can spell on a standard phone keypad, in lexicographic order. It tests systematic enumeration of combinations, keys that carry four letters, and producing a deterministic output order.
Coding & AlgorithmsTechnical Screen - HeadwayHardSoftware EngineerImplement Journey Counter and Speeder Detector
This problem tests your ability to process time-series event data by grouping related actions, managing state across sequences, and performing geometric or threshold-based calculations.
Coding & AlgorithmsTechnical ScreenHash MapsTime-SeriesState Management - HebbiaMediumSoftware EngineerImplement Ultimate Tic-Tac-Toe
This problem tests your ability to design a state-management system for a nested game board and implement recursive winner-detection logic.
Coding & AlgorithmsTechnical ScreenOODState ManagementGame Theory - Hive.AiHardSoftware EngineerDetect a Reachable Negative Cycle
This problem tests the implementation of the Bellman-Ford algorithm to identify negative cycles reachable from a source vertex, specifically requiring careful handling of unreachable nodes to avoid incorrect cycle detection.
Coding & AlgorithmsTechnical ScreenGraphsShortest-PathBellman-Ford - Hive.AiHardSoftware EngineerMeasure Water Trapped Between Elevations
This problem tests the ability to solve a classic dynamic programming/two-pointer challenge by calculating the volume of trapped water between bars of varying heights.
Coding & AlgorithmsTechnical ScreenArraysTwo PointersDynamic Programming - Hive.AiHardSoftware EngineerTrack the Median of a Stream
This problem tests your ability to maintain sorted order in a streaming context using balanced data structures to achieve optimal time complexity for insertions and median retrieval.
Coding & AlgorithmsTechnical ScreenHeapsData StructuresStreaming Algorithms - Hive.AiHardSoftware EngineerValidate Adding an Edge to a Directed Acyclic Graph
This problem tests your ability to manipulate graph structures and implement reachability checks, specifically ensuring that adding an edge to a Directed Acyclic Graph (DAG) maintains its acyclic property.
Coding & AlgorithmsTechnical ScreenGraphsDAGDFS/BFS - HubSpotMediumSoftware EngineerValidate hiring request under role constraints
This problem tests your ability to manage state mapping and validate cardinality constraints using hash maps, requiring efficient lookups to ensure hiring requests remain within predefined role limits.
Coding & AlgorithmsTechnical ScreenHash MapsData ValidationState Management - Hudson River TradingMediumSoftware EngineerApproach verbose data-structure design
This question evaluates a candidate's ability to design and implement complex data structures, testing algorithmic reasoning, time/space complexity analysis, state modeling, and organization of code and tests.
Coding & AlgorithmsTechnical Screen - Hudson River TradingEasySoftware EngineerBall Position in a Tilting Maze After Timed Tilt Events
Live coding simulation problem: a ball sits in a grid maze on a board that can tilt up, down, left or right or lie flat, and timed events change the tilt. Return the ball's cell at an end time that can be very large. It tests precise timing rules, wall handling and movement code that scales to long time spans.
Coding & AlgorithmsTechnical Screen - Hudson River TradingMediumSoftware EngineerCalculate Completion Time for a Single-Server Reactor Queue
Simulate a single-threaded reactor queue with a bounded buffer to compute the completion timestamp or drop status for each incoming task.
Coding & AlgorithmsTechnical ScreenQueueSimulationArrays - Hudson River TradingEasySoftware EngineerCheck Root-To-Leaf Target Sums In A Binary Tree
This question tests your ability to traverse a binary tree using depth-first search (DFS) or breadth-first search (BFS) while tracking path accumulators and accurately identifying valid leaf nodes.
Coding & AlgorithmsTechnical ScreenBinary TreeDFSRecursion - Hudson River TradingMediumSoftware EngineerCount Digit-Reversal Equivalent Pairs
Count pairs of indices in an integer array whose values share the same canonical digit-reversal form.
Coding & AlgorithmsTechnical ScreenHash TableMathString - Hudson River TradingMediumSoftware EngineerCount Length-3 Chat Substrings with a Vowel
Count the number of distinct length-3 alphabetical substrings in a chat message that contain at least one vowel.
Coding & AlgorithmsTechnical Screenstringsliding-windowhash-set - Hudson River TradingMediumData ScientistCount inversions in a permutation
This question evaluates understanding of inversion counting in permutations, testing algorithmic problem-solving, complexity analysis, and data-structure reasoning about pairwise order relations.
Coding & AlgorithmsTechnical Screen - Hudson River TradingEasySoftware EngineerCount players reaching end with moving watchers
This problem tests your ability to model state transitions over discrete time steps and efficiently track interval coverage using sorting and sweep-line logic.
Coding & AlgorithmsTechnical ScreenSimulationGeometryOptimization - Hudson River TradingMediumSoftware EngineerDetermine Whether Two Integers Sum to a Target
This problem tests proficiency with hash sets to achieve linear time complexity and emphasizes defensive programming practices like input validation and immutability.
Coding & AlgorithmsTechnical ScreenHash SetArraysTwo Pointers - Hudson River TradingHardSoftware EngineerFinal Grid Position Under Timestamped Direction Changes With Dot Obstacles
An object on a grid changes direction whenever a timestamped action arrives and moves one cell per time unit until a blocked cell or the grid edge stops it. The task asks for its cell at a given end time, testing precise reading of the rules, including that dot cells are obstacles, and efficient handling of very large timestamps.
Coding & AlgorithmsTechnical Screen - Hudson River TradingMediumSoftware EngineerFormat an Integer with Thousands Separators
Implement a function that formats a signed integer with a custom thousands separator character without relying on built-in string formatting utilities.
Coding & AlgorithmsTechnical Screenstringmathimplementation - Hudson River TradingMediumSoftware EngineerReturn the K Smallest Integers
Implement an algorithm to extract the k smallest integers from an unsorted list in ascending order, preserving duplicates, and analyze the trade-offs between sorting, heaps, quickselect, and bounded-range approaches.
Coding & AlgorithmsTechnical ScreenHeapQuickselectSorting
Harvey
HubSpot
Hudson River Trading