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 1081–1110 of 3276 results
This question evaluates array and matrix manipulation, stateful simulation of game mechanics, and handling edge cases such as merge constraints, single-merge-per-move rules, and empty-cell management.
GleanSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates a candidate's ability to implement array and matrix manipulation, deterministic state-transition logic, and rule-based merging behavior in a grid-based simulation.
GleanSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates a candidate's ability to implement a rate-limited web crawler, testing skills in crawl frontier management, prioritization by page-title initial, deduplication, rate limiting, and robust error handling.
GleanMachine Learning EngineerCoding & AlgorithmsOnsiteImplement a Byte Pair Encoding (BPE) tokenizer with training, encoding, and decoding capabilities using frequency-based iterative merging.
GleanSoftware EngineerCoding & AlgorithmsTechnical ScreenReplace every value in a matrix of distinct integers with the smallest rank such that larger values outrank smaller ones within each row and column. Tests processing values in sorted order, tracking per-row and per-column state, and the one-dimensional special case.
GleanSoftware EngineerCoding & AlgorithmsOnsiteRestore a nearly sorted array where at most one element has been removed and reinserted elsewhere, in linear time and without mutating the input array.
GleanSoftware EngineerCoding & AlgorithmsTechnical ScreenDesign an in-memory prefix search system that returns the top-k department suggestions based on popularity scores, with deterministic tie-breaking.
GleanSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates algorithmic problem-solving in grid traversal and multi-word string search, targeting competencies in pathfinding, string matching, efficient use of data structures for shared prefixes, and time/space complexity analysis within the Coding & Algorithms domain.
GleanSoftware EngineerCoding & AlgorithmsTechnical ScreenFind the shortest distance between any X and any Y, first in a string and then in a 2D grid using Manhattan distance, returning -1 when one letter is missing. Tests moving from a linear scan to multi-source breadth-first search and reasoning about efficiency on large grids.
GleanSoftware EngineerCoding & AlgorithmsOnsiteSimulate documents assigned to indexers by index modulo m, falling through to the next free indexer with wrap-around and dropping documents when all are busy, then report processed totals, the busiest indexer and the top-k share. Tests event simulation, finding the next free slot efficiently and precise tie rules.
GleanSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates simulation of parallel worker scheduling, time-based queue processing, modular assignment logic, and aggregation/ranking (top-k and percentage) competencies for tracking per-worker workloads.
GleanSoftware EngineerCoding & AlgorithmsTechnical ScreenGiven an array that was sorted until one element was moved to another position, return it sorted again in linear time without a full sort. Tests locating the displaced element in either direction, handling duplicates and already-sorted input, and reasoning about O(n) time with constant extra space.
GleanSoftware EngineerCoding & AlgorithmsOnsiteTests dynamic programming on a grid to find an optimal path from the bottom-left to top-right corner using constrained directional moves.
Goldman SachsSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates implementation skills in supervised machine learning and numerical optimization, specifically computing Gini impurity and selecting optimal binary splits for a decision tree alongside deriving and applying a single-step gradient descent update for linear regression.
Goldman SachsMachine Learning EngineerCoding & AlgorithmsOnline AssessmentThis question tests your ability to identify palindromes within a string using expansion around centers or dynamic programming.
Goldman SachsData ScientistCoding & AlgorithmsOnline AssessmentThis two-part problem evaluates array-processing and counting competency for identifying fixed-length strictly increasing subarrays and combinatorial partitioning and optimization competency for assigning elements to three groups to maximize a minimal pairwise-difference metric, and is commonly asked to assess efficient algorithm design, correctness under constraints, and the ability to handle large inputs. Belonging to the Coding & Algorithms domain, it tests practical algorithmic application, data-structure-aware implementation and complexity analysis rather than purely theoretical understanding.
Goldman SachsSoftware EngineerCoding & AlgorithmsOnline AssessmentThis problem tests your ability to design a tree-based hierarchical resource management system and implement efficient operations for path-based access, relocation, and cycle detection.
Goldman SachsSoftware EngineerCoding & AlgorithmsTechnical ScreenGiven a list of child-to-parent pairs that form a forest of rooted trees, return the root ID of the tree with the most nodes, breaking size ties by the smallest root ID. Tests building a forest from an edge list, identifying roots, counting tree sizes, and applying a precise tie-break rule.
Goldman SachsSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates competence with fundamental data structures and algorithms by requiring an implementation of a string double-ended queue (deque), checking understanding of constant-time (O(1)) operations, manipulation of node links or references, and correct handling of edge cases; category: Coding & Algorithms; level: practical implementation rather than purely conceptual. It is commonly asked to assess the ability to implement low-level data structure mechanics, guarantee performance bounds, and expose attention to correctness and boundary conditions in algorithmic coding tasks.
Goldman SachsSoftware EngineerCoding & AlgorithmsTechnical ScreenTests sorting and sliding window techniques to maximize an element's frequency within an increment budget.
Goldman SachsSoftware EngineerCoding & AlgorithmsOnsiteGiven a complete matrix of possibly asymmetric travel costs between up to 16 cities, return the minimum cost of a round trip that starts at city 0, visits every other city exactly once and returns to city 0. The problem tests exact optimization over subsets of cities within tight limits.
Goldman SachsQuantitative ResearcherCoding & AlgorithmsTechnical ScreenThis problem tests your ability to model a grid-based movement simulation as a graph reachability problem, requiring efficient state traversal.
Goldman SachsSoftware EngineerCoding & AlgorithmsOnsiteTests the ability to search efficiently in a 2D grid sorted along both dimensions by exploiting boundary invariants to achieve an O(m + n) time complexity.
Goldman SachsSoftware EngineerCoding & AlgorithmsOnsiteThis problem tests your ability to manipulate strings, utilize hash maps for grouping data, and perform iterative simulations based on sequential command logs.
Goldman SachsSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates proficiency in string manipulation and hash-based aggregation, specifically skills such as frequency counting, map/dictionary usage, and numeric aggregation for averages.
Goldman SachsSoftware EngineerCoding & AlgorithmsTechnical ScreenGiven the heights of adjacent unit-width bars in an elevation profile, compute the total amount of rainwater that stays trapped between them after rain, with water spilling off both open ends. The coding problem tests reasoning about the bars that bound each position and handling up to 100,000 bars efficiently.
Goldman SachsQuantitative ResearcherCoding & AlgorithmsTechnical ScreenThis question evaluates algorithmic skills in manipulating linked lists or arrays to perform addition of large integers, focusing on carry propagation, handling differing lengths, and analysis of time and space complexity.
GoogleSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests your ability to use prefix sums or dynamic tracking to determine if a range [L, R] consists of elements that alternate between odd and even parity in O(1) time after O(N) preprocessing.
GoogleSoftware EngineerCoding & AlgorithmsTechnical ScreenArrange exact crop counts into connected grid regions, prove a rectangular construction, and analyze the geometry needed for a two-square garden follow-up.
GoogleSoftware EngineerCoding & AlgorithmsOnsiteDetermine the minimum fleet size and a deterministic vehicle assignment for a list of rental reservations using interval scheduling and priority queues.
GoogleSoftware EngineerCoding & AlgorithmsOnsite