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 1831–1860 of 3276 results
This problem tests your ability to use a monotonic stack and a hash map (or frequency array) to efficiently answer suffix queries about the occurrences of the maximum value.
MicrosoftSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates understanding of number theory and algorithmic problem-solving, focusing on Diophantine equation manipulation, divisor counting, and translating algebraic constraints into combinatorial counts.
MicrosoftSoftware EngineerCoding & AlgorithmsOnline AssessmentThis question evaluates number-theoretic reasoning and understanding of arithmetic progressions, focusing on how sums of consecutive positive integers can be characterized and counted.
MicrosoftSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates combinatorics and constrained counting skills, including reasoning about digit-sum properties, monotonic sequences, modular arithmetic, and efficient algorithm design within the Coding & Algorithms domain.
MicrosoftSoftware EngineerCoding & AlgorithmsTechnical ScreenA coding exercise that counts the separate land regions in a grid map of land and water cells, where land cells connect only through shared edges. It tests systematic exploration of a two-dimensional grid, correct neighbor handling at borders and corners, and scaling to large grids where one region may cover everything.
MicrosoftSoftware EngineerCoding & AlgorithmsOnsiteThis problem tests your understanding of the JSON Web Token (JWT) structure and your ability to manually implement Base64URL decoding and JSON deserialization in a constrained environment.
MicrosoftSoftware EngineerCoding & AlgorithmsOnsiteThis problem tests your ability to design a data structure that supports storing multiple values for the same key indexed by timestamps, requiring efficient retrieval of the latest value at or before a specific point in time.
MicrosoftSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates understanding of in-memory key–value cache design, eviction policies, and appropriate data-structure choices to achieve amortized O(1) get and put operations.
MicrosoftSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests string manipulation, hashing, and the ability to detect repeating sub-sequences of a fixed length k across a stream.
MicrosoftSoftware EngineerCoding & AlgorithmsTechnical ScreenThis interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Determine most popular concert city states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
MicrosoftSoftware EngineerCoding & AlgorithmsTechnical ScreenA coding question that asks for the fewest distinct values whose complete deletion removes at least half of an integer array. It tests reasoning about how often each value occurs, proving that a choice is minimal, and the exact meaning of half when the array length is odd.
MicrosoftApplied ScientistCoding & AlgorithmsOnsiteThis question tests the ability to efficiently find the K largest elements in an unsorted array while managing time complexity constraints through heap-based or selection-based algorithms.
MicrosoftMachine Learning EngineerCoding & AlgorithmsTechnical ScreenFind unique zero-sum triplets with distinct indices, deterministic ordering, careful duplicate suppression, and explicit time and space analysis.
MicrosoftSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates understanding of permutations, array range reasoning, index mapping, and efficient algorithm design for detecting contiguous subarrays that exactly contain the prefix set {1..k}.
MicrosoftSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests your ability to use the sliding window technique combined with a hash map to efficiently find a maximal subarray meeting a specific constraint.
MicrosoftSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates understanding of tree data structures and the lowest common ancestor concept, contrasting use of binary search tree ordering with the general binary tree case while requiring algorithmic time and space complexity reasoning in the Coding & Algorithms domain.
MicrosoftSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates algorithmic problem-solving with arrays, including reasoning about contiguous subsequences, handling sorted inputs and edge cases, and analyzing time and space complexity.
MicrosoftSoftware EngineerCoding & AlgorithmsOnline AssessmentThis problem tests your ability to identify cycles within a weighted directed graph and compute the ratio of cycle cost to node count efficiently.
MicrosoftSoftware EngineerCoding & AlgorithmsOnline AssessmentThis question evaluates array manipulation, sorting-based reasoning, and the ability to generate ordered value pairs that reflect minimum absolute differences while handling ordering and duplicates.
MicrosoftMachine Learning EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates proficiency in string processing, frequency management, and algorithmic optimization for locating constrained contiguous substrings. Commonly asked in the coding & algorithms domain because it reveals how candidates reason about character distinctness and efficiency trade-offs, it targets practical application of algorithmic techniques rather than purely conceptual theory.
MicrosoftSoftware EngineerCoding & AlgorithmsOnsiteCompute the maximum weight connected subgraph containing each node in a tree with +1 and -1 neuron weights using rerooting dynamic programming.
MicrosoftSoftware EngineerCoding & AlgorithmsOnline AssessmentThis problem tests the ability to leverage the Binary Search Tree (BST) property to efficiently locate the Lowest Common Ancestor (LCA) of two nodes.
MicrosoftMachine Learning EngineerCoding & AlgorithmsHR ScreenThis problem tests tree traversal techniques and recursion logic to identify the deepest node that is an ancestor to two specified nodes in an arbitrary binary tree.
MicrosoftMachine Learning EngineerCoding & AlgorithmsHR ScreenDetermine the most frequently visited track position given a series of sprint endpoints by efficiently tallying overlapping intervals.
MicrosoftSoftware EngineerCoding & AlgorithmsOnsiteCoding practice question: two singly linked lists that may merge into a shared tail are given as sequences of node ids, and you must return the id of the node where they first meet, or -1. It tests reasoning about linked list structure, linear-time traversal, and edge cases such as no shared node or one list being the other's tail.
MicrosoftSite Reliability EngineerCoding & AlgorithmsOnsiteThis problem tests your ability to model a network as a graph and perform partitioning to optimize internal connectivity constraints.
MicrosoftSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates understanding of graph theory concepts—directed trees, parent-child constraints, and cycle detection—and measures competency in reasoning about how a single extra directed edge can violate rooted-tree properties.
MicrosoftSoftware EngineerCoding & AlgorithmsOnsiteThis problem tests your ability to parse structured meeting request strings into interval objects and then identify the largest subset of non-overlapping meetings that can be scheduled within a fixed workday.
MicrosoftSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates a candidate's ability to implement an iterative clustering algorithm (K-means) and to reason about subarray sums modulo k, testing competencies in numerical computation, centroid management, edge-case handling, and efficient algorithm design.
MicrosoftMachine Learning EngineerCoding & AlgorithmsOnsiteThis problem tests in-place array manipulation for submatrix coordinate transformations and the implementation of a thread-safe, time-windowed rate limiter using a sliding window approach.
MicrosoftSoftware EngineerCoding & AlgorithmsOnsite