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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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- 11
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Showing 31–60 of 3276 results
- AgodaEasyData EngineerCount Integers That Appear Exactly Once
Count distinct integers with frequency exactly one using complete occurrence counts, including empty arrays and separated duplicates.
Coding & AlgorithmsTechnical Screen - AgodaMediumSoftware EngineerFind two numbers that sum to a target
This question evaluates array manipulation, index-based reasoning, and algorithmic problem-solving skills related to identifying value pairs that meet a numeric target.
Coding & AlgorithmsTechnical Screen - Ai2MediumSoftware EngineerMaintain an Out-of-Order Step Progress Tree
This problem tests tree reconstruction from a stream of out-of-order parent-child updates, requiring efficient hierarchical state management and cycle detection.
Coding & AlgorithmsTechnical ScreenTreesGraphsData Structures - Aim Intelligent MachineMediumSoftware EngineerMerge Overlapping Closed Intervals into a Sorted Disjoint List
Tests sorting and linear scanning techniques to merge overlapping closed intervals, with attention to shared boundaries, nested ranges, and large input scale.
Coding & AlgorithmsTechnical ScreenIntervalsSortingArray - AirbnbMediumSoftware EngineerAllocate an Order from the Oldest Inventory Batches
Implement a function to allocate an order across inventory batches using FIFO (oldest timestamp first, with batch ID tie-breaker), returning allocation details and any unfilled quantity without mutating the input.
Coding & AlgorithmsOnsitesortinggreedyarrays - AirbnbMediumSoftware EngineerAllocate refund across payments
This question evaluates algorithm design and data-structure selection skills, focusing on greedy allocation, ordering by priority and recency, aggregation of transaction amounts, and analysis of time complexity.
Coding & AlgorithmsOnsite - AirbnbMediumSoftware EngineerCompute board-game score from regions
This problem tests your ability to identify connected components in a 2D grid using graph traversal (BFS/DFS) and aggregate properties associated with those components.
Coding & AlgorithmsOnsiteGraph TraversalBFSDFS - AirbnbMediumSoftware EngineerCompute minimum-cost service cover
This question evaluates proficiency in combinatorial optimization and set-coverage with cost minimization, including handling case-insensitive service matching and enumerating minimal solution combinations.
Coding & AlgorithmsTechnical Screen - AirbnbMediumSoftware EngineerCompute split-stay listing pairs
This question evaluates the ability to manipulate interval availability data, reason about contiguous date ranges and split boundaries, and design efficient pairing algorithms with attention to time and space complexity.
Coding & AlgorithmsTechnical Screen - AirbnbMediumSoftware EngineerConstruct smallest number from I/D pattern
This problem tests greedy algorithm design and stack-based data structure manipulation to satisfy relative ordering constraints within a sequence of digits.
Coding & AlgorithmsTechnical ScreenGreedyStackStrings - AirbnbMediumSoftware EngineerCount Candies from Unlockable Boxes
Determine the maximum number of candies you can collect given an initial set of boxes, where each box may be locked or unlocked, contain candies, contain keys to other boxes, and contain other boxes.
Coding & AlgorithmsTechnical ScreenBreadth-First SearchGraphQueue - AirbnbHardSoftware EngineerCount Consecutive Positive Integer Sums
Count representations of a positive integer as one or more consecutive positive integers, including the one-term representation. Derive the arithmetic condition for each sequence length and use a square-root bound rather than testing every possible starting value.
Coding & AlgorithmsOnsite - AirbnbMediumSoftware EngineerDesign and implement Connect Four engine
This question evaluates a candidate's competency in algorithmic problem solving, data structure selection, API design, complexity analysis, and testing through implementation of a Connect Four game engine.
Coding & AlgorithmsTechnical Screen - AirbnbMediumSoftware EngineerDesign mutable sum-tree with fast queries
This question evaluates proficiency in designing dynamic data structures for mutable rooted trees, including maintenance of subtree sums, parent/child link management, and analysis of update and query complexities within the Coding & Algorithms domain; it emphasizes practical application of algorithmic design coupled with conceptual understanding of invariants and amortized complexity. It is commonly asked in technical interviews because it probes reasoning about correctness and performance under mutations, handling edge cases such as subtree deletion and reattachment, and the ability to specify algorithmic approaches and complexity guarantees rather than implementation details.
Coding & AlgorithmsOnsite - AirbnbHardSoftware EngineerDetect overlap of two linked lists with cycles
This problem tests your ability to detect if two linked lists merge, specifically when they may contain cycles, by requiring logic to identify loop entry points and intersection nodes.
Coding & AlgorithmsOnsiteLinked ListTwo PointersCycle Detection - AirbnbMediumSoftware EngineerDetermine Exact Layover Booking
Determine if a subset of layover activities can be booked such that their total cost exactly matches a target voucher balance, handling floating-point currency without precision loss.
Coding & AlgorithmsTechnical ScreenDynamic ProgrammingBacktrackingSubset Sum - AirbnbMediumSoftware EngineerFind minimal property set in neighborhood
This question evaluates combinatorial optimization and algorithm design skills, focusing on capacity-constrained selection (subset-sum/knapsack-style reasoning), deterministic tie-breaking, and complexity analysis within the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - AirbnbMediumSoftware EngineerFind palindrome-forming string pairs
This question evaluates string-processing and algorithmic design skills, including knowledge of efficient lookup data structures, palindrome properties, handling of edge cases, and time/space complexity analysis.
Coding & AlgorithmsOnsite - AirbnbMediumSoftware EngineerFind smallest permutation under constraints
This problem tests your ability to manipulate digits and understand greedy strategies to construct the smallest possible number after applying specific constraints.
Coding & AlgorithmsOnsiteGreedyRecursionStrings - AirbnbHardSoftware EngineerFlatten a Nested Integer List
Flatten an arbitrarily deep mixture of integers and lists while preserving left-to-right order. The challenge emphasizes an iterative stack solution that handles empty lists, very deep nesting, and up to 200,000 nodes without mutating the input.
Coding & AlgorithmsOnsite - AirbnbMediumSoftware EngineerImplement Connect Four game
This question evaluates implementation skills for game state management, move handling, and efficient winner-detection algorithms, testing competence in data structures, algorithmic complexity analysis, and correctness under edge cases.
Coding & AlgorithmsTechnical Screen - AirbnbMediumSoftware EngineerImplement Connect Four with win detection
This question evaluates a candidate's ability to design efficient data structures and algorithms for real-time game state management, including win detection, API design, time/space complexity analysis, and handling edge cases such as full or out-of-range columns.
Coding & AlgorithmsOnline Assessment - AirbnbEasySoftware EngineerImplement Text Layout and Query Parsing
Implement URL query parameter extraction and a greedy text line-wrapper that enforces maximum line length and prevents orphan words on the final line.
Coding & AlgorithmsTechnical ScreenStringsParsingGreedy - AirbnbEasySoftware EngineerImplement a Removable Nested-List Iterator
Design and implement a nested-list iterator supporting `hasNext`, `next`, and an in-place `remove` operation that alters the original data structure.
Coding & AlgorithmsTechnical ScreenDesignStackRecursion - AirbnbMediumSoftware EngineerMaximize path score in DAG
This question evaluates proficiency in graph algorithms and optimization, focusing on reasoning about weighted directed acyclic graphs and maximizing a path score that combines node rewards and edge time costs.
Coding & AlgorithmsTechnical Screen - AirbnbMediumSoftware EngineerMaximize profit from non-overlapping jobs
This question evaluates proficiency in weighted interval scheduling, dynamic programming concepts, and the use of efficient data structures for large-scale scheduling problems, including handling duplicate times, large reward values, and memory constraints.
Coding & AlgorithmsOnsite - AirbnbHardSoftware EngineerMaximize sum with no adjacent tree nodes
This problem tests your ability to use tree-based dynamic programming to solve an optimization challenge where you must select a subset of nodes with no two being adjacent, while maximizing the sum of their values.
Coding & AlgorithmsOnsiteTree DPRecursionDFS - AirbnbMediumMachine Learning EngineerMinimize exact layover bookings
This problem tests your ability to use dynamic programming to determine if a specific target sum can be achieved using a subset of given item values and how to find the minimum subset size that hits that target.
Coding & AlgorithmsOnsiteDynamic ProgrammingOptimizationAlgorithms - AirbnbMediumMachine Learning EngineerMinimum Canisters to Top Up an Exact Target
Tests dynamic programming for the unbounded knapsack/coin change problem, focusing on finding the minimum number of canisters to reach an exact volume and reconstructing the optimal selection.
Coding & AlgorithmsTechnical Screendynamic-programmingknapsackarrays - AirbnbHardSoftware EngineerProcess a Timestamped Workspace Credit Ledger
Design and implement an in-memory timestamped credit ledger that supports deposits, transfers, spending with delayed cashback rewards, account merges, balance queries, and spend rankings.
Coding & AlgorithmsOnline AssessmentData StructuresDesignHeap
Agoda
Airbnb