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 2671–2700 of 3276 results
Minimize a bus fleet when trips have origin and destination stations, tracking when buses become available at the correct departure station.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenFind the minimum number of buses needed for a timetable by tracking overlapping trips and allowing reuse at equal arrival and departure times.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenDesign a data structure that tracks characters in a dynamic string, supporting streaming appends, character updates, and fast queries for the distance to the nearest target character.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenGiven a board size and the sequence of columns two players drop pieces into, return which player first lines up four pieces horizontally, vertically or diagonally, or 0 if nobody does. It tests grid simulation, gravity placement and careful line counting in all four directions.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenGiven an N-ary tree as a parent array and a set of nodes to delete, where each deleted node's children are promoted to its nearest surviving ancestor, return the height of the resulting tree. It tests tree traversal over a parent array and careful reasoning about how deletions change depths.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenEach job has a start time, an end time and a profit; choose jobs that do not overlap, where one job may start exactly when another ends, to maximize the total profit. It tests weighted interval scheduling and handling touching endpoints correctly.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates mastery of graph algorithms—specifically depth-first search (both recursive and iterative), directed cycle detection, topological ordering, and discovery/finish timestamping—and falls under the Coding & Algorithms domain.
SnowflakeData ScientistCoding & AlgorithmsTechnical ScreenThis problem tests your ability to implement a recursive-descent parser for a subset of the JSON format, focusing on string manipulation, state management, and hierarchical data structure construction.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests your understanding of the observer pattern, internal state management using maps, and the ability to handle edge cases in listener lifecycle management.
SnowflakeFrontend EngineerCoding & AlgorithmsTechnical ScreenThis combined question evaluates proficiency in graph-based dependency reasoning (cycle detection and course scheduling) and time-series request processing (rate-limiter behavior and sliding-window request counting) within the Coding & Algorithms domain.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates competencies in web crawling and string validation, covering graph traversal and cycle avoidance with domain filtering for crawl discovery, and delimiter matching with error indexing for multi-type bracket validation.
SnowflakeSoftware EngineerCoding & AlgorithmsOnsiteThese tasks evaluate core competencies in directed graph algorithms (topological ordering and cycle detection) and binary tree traversals (boundary identification and leaf enumeration), testing understanding of dependency modeling and traversal patterns.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenGiven a binary tree stored as child-index arrays and two node indices, return the nodes on the unique path between them, from the first node to the second. It tests parent tracking, ancestor reasoning and handling cases where one node lies above the other.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests greedy optimization and modular arithmetic skills to determine the most profitable query strategy given a limited time window.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests your ability to optimize combinatorial decisions under constraints by identifying a greedy approach with a fallback to search or dynamic programming.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenCourses take different numbers of months, some must finish before others start, and any number can run in parallel; return the minimum time to finish them all. It tests longest-path reasoning on a directed acyclic graph processed in topological order.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenGiven an N-ary tree as a parent array and a limit k, find the fewest non-root nodes to delete, promoting each deleted node's children to its nearest surviving ancestor, so that the tree's height is at most k. It tests reasoning about root-to-leaf paths and choosing deletions that shorten many paths at once.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenGiven a directory tree where deleting a node reattaches its children to its own parent, find the minimum number of deletions needed to bring the deepest root-to-leaf path down to a given limit. Tests a budget-passing tree DP where deleting a node changes how much depth its children inherit.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenGiven a list of items such as trending words or bestselling book titles and a number k, return the k most frequent items ordered by count, with ties broken alphabetically. It tests frequency counting, sorting with a compound key and heap-based selection.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenEach meeting can be attended on any single day within its range, and only one meeting fits on each day; return the largest number of meetings you can attend. It tests interval scheduling reasoning and an exchange argument for why a local choice stays optimal.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenGiven an N-ary tree as a parent array and a set of nodes to delete, move each deleted node's children up to its nearest surviving ancestor and report the height of the resulting tree. Tests building a tree from parent links, reasoning about cascading deletions, and computing depths on a tree that can be a path of 100,000 nodes.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenGiven a flat list of (person, supervisor) ID pairs, reconstruct the organization as a forest rooted at whoever has no supervisor, then emit a deterministic preorder listing of (id, depth). Tests root detection, building ordered adjacency lists, and careful DFS ordering.
SnowflakeSoftware EngineerCoding & AlgorithmsOnsiteGiven a directed acyclic graph in which each node grants and revokes letter permissions, compute every node's final set of letters when each node passes only its final state to its children. Tests topological processing, set propagation over multiple parents, and letters that descendants grant again after an ancestor revokes them.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenDesign an in-memory event tracker that maintains the most recent m arrivals from a timestamped stream and efficiently queries distinct key counts and top-frequency keys above a cutoff timestamp.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenReplay a sequence of push/pop/peek/min-read operations on a stack of freezer temperature readings and return what each read produces, where reading the current minimum must be as fast as pushing or popping. Tests pairing a stack with running-minimum bookkeeping that stays correct through duplicate minimums and repeated pops.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenFind a deterministic, lexicographically smallest topological order of all direct and indirect prerequisites for a specific target course while ignoring cycles outside the target's dependency subgraph.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenReverse a string given as an array of characters in place, using only constant extra memory, and return the same list. A short coding warm-up that tests index handling, swapping elements and odd and even lengths without building a copy.
SnowflakeSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests your ability to model dependencies using a Directed Acyclic Graph (DAG) and perform a topological sort while accounting for re-take conditions.
SnowflakeSoftware EngineerCoding & AlgorithmsOnsiteSnowflake software-engineer onsite coding question: design a compact, robust wire format to serialize and deserialize a dictionary trie. Covers DFS vs BFS encodings, delimiter vs length-prefix framing and escaping, explicit end-of-word markers, streaming, malformed/partial-input handling, forward/backward compatibility, Unicode, compression, memory limits, and O(N) complexity.
SnowflakeSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates array-processing and graph-algorithm skills, specifically minimum-distance computation between marked elements in a one-dimensional array and shortest-path navigation in a directed link graph, plus edge-case reasoning and test-case design.
SnowflakeSoftware EngineerCoding & AlgorithmsOnline Assessment