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 1771–1800 of 3276 results
This problem tests your ability to handle frequency counting and constraint-based pair identification efficiently, often requiring a hash map to maintain counts while traversing a stream.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenThis collection evaluates proficiency with fundamental data structures and algorithmic techniques — including matrix and graph traversal, hash-based sets for O(1) operations, linked list manipulation, sliding-window strategies, recursive processing of nested structures, and stack/string handling — along with complexity analysis and reliable implementation. Commonly asked in the Coding & Algorithms domain, these problems assess pattern recognition, algorithmic reasoning, and practical implementation skills under time and space constraints, emphasizing applied problem-solving over purely theoretical concepts.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenThis set of coding tasks evaluates fundamental skills in array manipulation, graph traversal, greedy strategy, and sequence analysis.
MetaSoftware EngineerCoding & AlgorithmsHR ScreenThis problem tests foundational proficiency in four distinct domains: string processing, array simulation, matrix transformation, and graph traversal.
MetaMachine Learning EngineerCoding & AlgorithmsOnline AssessmentThis multi-part question evaluates algorithmic problem-solving and data-structure proficiency across string processing (validating parentheses with minimal deletions), tree operations (lowest common ancestor using parent pointers), nested-structure traversal and accumulation (depth-weighted sum), and geometric selection/ordering (k closest points).
MetaSoftware EngineerCoding & AlgorithmsOnsiteThis set of tasks evaluates core algorithmic competencies such as tree traversal and level-order processing, data-structure design and counting maps, recursive subtree aggregation for statistical checks, and optimization/search techniques for partitioning problems, all within the Coding & Algorithms domain.
MetaSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates proficiency in graph traversal and pathfinding, state representation for unknown environments, exploration and backtracking, and rigorous reasoning about correctness and time/space complexity.
MetaSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates algorithmic problem-solving in grid reachability and frequency analysis, testing concepts such as grid/graph traversal and obstacle handling for path existence alongside frequency counting and selection for top-k elements.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates a candidate's ability to implement grid-based graph traversal and stateful simulation, assessing skills in shortest-path search and systematic exploration for cleaning tasks.
MetaSoftware EngineerCoding & AlgorithmsOnsiteSolve increasing sequence and path problems 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.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenThese problems evaluate graph traversal and connected-component identification in 2D grids plus frequency analysis and selection in arrays, covering concepts such as DFS/BFS, Union-Find, hashing, heaps and bucket sort.
MetaSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates graph connectivity reasoning (computing minimum edges to unify components) and string-based big-integer arithmetic (multiplying numbers represented as strings), testing competency in graph theory, component analysis, and numeric string manipulation.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenSolve library coding tasks in Python 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.
MetaData EngineerCoding & AlgorithmsTechnical ScreenThis set evaluates mastery of core data structures and algorithmic reasoning across singly linked lists (cycle entry detection), binary search trees with parent pointers (in-order successor), constant-time state tracking for n×n game boards, and grid connectivity for maximizing component size, emphasizing pointer manipulation, traversal logic, state-design, and component analysis. Commonly asked to gauge proficiency in Coding & Algorithms and complexity analysis, these problems test both conceptual understanding of traversal and connectivity principles and practical application of space- and time-efficient implementations under typical interview constraints.
MetaMachine Learning EngineerCoding & AlgorithmsOnsiteThis question evaluates competency in fundamental data structures and algorithmic techniques, including linked list manipulation, frequency counting and top‑K retrieval, closest-point geometric queries, and stack-based string processing for repeated deletions.
MetaSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates algorithmic problem-solving across grid and graph algorithms, selection algorithms, and traversal techniques—specifically connected-component detection in binary matrices, median-finding across two sorted arrays, and BFS/DFS traversal variants—measuring competence in data structures, complexity analysis, and handling edge cases. Commonly asked in Coding & Algorithms interviews for Machine Learning Engineer roles, it assesses efficiency and correctness concerns such as time and space complexity and traversal orders, testing both conceptual understanding of algorithmic principles and practical implementation distinctions like iterative versus recursive variants.
MetaMachine Learning EngineerCoding & AlgorithmsTechnical ScreenSolve matrix diagonal and sliding-window statistics 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.
MetaMachine Learning EngineerCoding & AlgorithmsTechnical ScreenThis prompt evaluates string-processing and tree-traversal competencies by asking whether a string can become a palindrome after at most one deletion and by requiring a vertical-order traversal of a binary tree, testing understanding of palindrome properties, node ordering, and handling of edge cases in the coding and algorithms domain.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates algorithmic design and data-structure skills by combining a binary-search peak-finding problem with a string-abbreviation uniqueness problem, testing competence in time-complexity reasoning and creation of minimal unique representations.
MetaSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates understanding of lexicographic permutation generation with in-place array manipulation and linear-time arithmetic expression parsing and evaluation, focusing on algorithmic efficiency, constant extra space constraints, and correct operator semantics.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenThe trio of problems — Minimum Remove to Make Valid Parentheses, Making a Large Island, and Binary Tree Right Side View — evaluates algorithmic problem-solving, proficiency with core data structures (strings, grids/graphs, and trees), and awareness of time and space complexity.
MetaSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates understanding of graph algorithms and pathfinding, covering tree diameter computation and grid shortest-path problems as well as enumeration of simple paths, and requires skills in traversal techniques, combinatorial reasoning, and time/space complexity analysis.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates proficiency in tree traversal and array search algorithms, specifically handling recursive depth-first traversal with path-based numeric accumulation and performing logarithmic-time search over sorted data.
MetaSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates algorithmic problem-solving and data-structure competency, focusing on binary tree traversal and column-wise ordering (including BFS versus DFS trade-offs) as well as interval merging and sorting strategies for scheduling.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenSolve tree traversal and two-pointer problems 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.
MetaSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates binary tree traversal and view-extraction skills for the right-side view problem and string-processing and minimal-edit balancing for the parentheses cleanup, probing competency in data-structure traversal, state tracking, and correctness under edge cases.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests your ability to manipulate linked list pointers to detect cycles and solve a classic array-based problem using the two-pointer technique to find specific target sums.
MetaMachine Learning EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates algorithm design and data-structure skills, focusing on weighted random selection and array aggregation for product computations within the Coding & Algorithms domain.
MetaSoftware EngineerCoding & AlgorithmsOnline AssessmentThis question evaluates proficiency in windowed duplicate detection and time-space trade-offs for streaming or bounded-range scans, along with combinatorial expression generation and on-the-fly numeric evaluation using search, reflecting skills in algorithm design, data-structure selection, and numeric correctness.
MetaSoftware EngineerCoding & AlgorithmsTechnical ScreenThis multipart question evaluates skills in tokenization and streaming text processing, generic rooted-tree data-structure design and traversal APIs, dictionary-based string segmentation (dynamic programming and prefix/prefix-structure optimization), and constrained algorithmic optimization for stock-trading problems.
MetaSoftware EngineerCoding & AlgorithmsOnsite