Topic
Coding & Algorithms interview questions
3276 Coding & Algorithms questions from 366 companies, with hints, runnable code and solution walkthroughs.
273 easy2539 medium464 hard
Coding & Algorithms interview questions by the numbers
Last updated
Katkat has 3,276 Coding & Algorithms interview questions from 366 companies; the most come from Amazon (7%), Meta (7%) and Google (6%). By difficulty: 8% easy, 78% medium and 14% hard. The most common round is Technical Screen (52%). Frequent concepts include Algorithms, Data Structures, Arrays and Greedy.
Companies (366)
Difficulty
- Easy8% · 273
- Medium78% · 2539
- Hard14% · 464
Interview rounds
- Technical Screen52% · 1706
- Onsite33% · 1080
- Online Assessment13% · 427
- HR Screen1% · 37
- Other1% · 26
Roles
- Software Engineer80% · 2629
- Machine Learning Engineer8% · 253
- Data Scientist7% · 241
- Data Engineer1% · 45
- Backend Engineer1% · 26
Frequent concepts
- Algorithms9% · 302
- Data Structures7% · 228
- Arrays5% · 176
- Greedy5% · 164
- Optimization5% · 151
- Hash Map4% · 124
Most mentioned in interview experiences
- 1.Solve Algorithmic Challenges in Online Coding Assessments15 reports
- 2.Solve LeetCode string and list problems11 reports
- 3.Solve sliding-window and heap problems8 reports
- 4.Implement LRU cache with O(1) ops7 reports
- 5.Implement and Analyze an LRU Query Cache6 reports
- 6.Determine Length of Longest Unique Substring5 reports
- 7.Match-3 Grid: Find Horizontal and Vertical Runs, Then Clear and Drop Cells5 reports
- 8.Design a single- and multi-threaded web crawler4 reports
- 9.Find an Exit in a URL Maze4 reports
- 10.Find deployable slots in a recurring week from allowed and freeze windows4 reports
Counted from 781 candidate interview experiences on Katkat. How we collect and count
Showing 31–60 of 3276 results
Count distinct integers with frequency exactly one using complete occurrence counts, including empty arrays and separated duplicates.
AgodaData EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates array manipulation, index-based reasoning, and algorithmic problem-solving skills related to identifying value pairs that meet a numeric target.
AgodaSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests tree reconstruction from a stream of out-of-order parent-child updates, requiring efficient hierarchical state management and cycle detection.
Ai2Software EngineerCoding & AlgorithmsTechnical ScreenTests sorting and linear scanning techniques to merge overlapping closed intervals, with attention to shared boundaries, nested ranges, and large input scale.
Aim Intelligent MachineSoftware EngineerCoding & AlgorithmsTechnical ScreenImplement 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.
AirbnbSoftware EngineerCoding & AlgorithmsOnsiteThis 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.
AirbnbSoftware EngineerCoding & AlgorithmsOnsiteThis problem tests your ability to identify connected components in a 2D grid using graph traversal (BFS/DFS) and aggregate properties associated with those components.
AirbnbSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates proficiency in combinatorial optimization and set-coverage with cost minimization, including handling case-insensitive service matching and enumerating minimal solution combinations.
AirbnbSoftware EngineerCoding & AlgorithmsTechnical ScreenThis 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.
AirbnbSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests greedy algorithm design and stack-based data structure manipulation to satisfy relative ordering constraints within a sequence of digits.
AirbnbSoftware EngineerCoding & AlgorithmsTechnical ScreenDetermine 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.
AirbnbSoftware EngineerCoding & AlgorithmsTechnical ScreenCount 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.
AirbnbSoftware EngineerCoding & AlgorithmsOnsiteThis 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.
AirbnbSoftware EngineerCoding & AlgorithmsTechnical ScreenThis 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.
AirbnbSoftware EngineerCoding & AlgorithmsOnsiteThis 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.
AirbnbSoftware EngineerCoding & AlgorithmsOnsiteDetermine 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.
AirbnbSoftware EngineerCoding & AlgorithmsTechnical ScreenThis 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.
AirbnbSoftware EngineerCoding & AlgorithmsTechnical ScreenThis 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.
AirbnbSoftware EngineerCoding & AlgorithmsOnsiteThis problem tests your ability to manipulate digits and understand greedy strategies to construct the smallest possible number after applying specific constraints.
AirbnbSoftware EngineerCoding & AlgorithmsOnsiteFlatten 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.
AirbnbSoftware EngineerCoding & AlgorithmsOnsiteThis 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.
AirbnbSoftware EngineerCoding & AlgorithmsTechnical ScreenThis 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.
AirbnbSoftware EngineerCoding & AlgorithmsOnline AssessmentImplement URL query parameter extraction and a greedy text line-wrapper that enforces maximum line length and prevents orphan words on the final line.
AirbnbSoftware EngineerCoding & AlgorithmsTechnical ScreenDesign and implement a nested-list iterator supporting `hasNext`, `next`, and an in-place `remove` operation that alters the original data structure.
AirbnbSoftware EngineerCoding & AlgorithmsTechnical ScreenThis 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.
AirbnbSoftware EngineerCoding & AlgorithmsTechnical ScreenThis 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.
AirbnbSoftware EngineerCoding & AlgorithmsOnsiteThis 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.
AirbnbSoftware EngineerCoding & AlgorithmsOnsiteThis 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.
AirbnbMachine Learning EngineerCoding & AlgorithmsOnsiteTests 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.
AirbnbMachine Learning EngineerCoding & AlgorithmsTechnical ScreenDesign and implement an in-memory timestamped credit ledger that supports deposits, transfers, spending with delayed cashback rewards, account merges, balance queries, and spend rankings.
AirbnbSoftware EngineerCoding & AlgorithmsOnline Assessment