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 151–180 of 3276 results
This problem tests your ability to solve a variation of the Traveling Salesman Problem using bitmask dynamic programming to optimize route costs in a small, weighted graph.
AmazonSoftware EngineerCoding & AlgorithmsOnline AssessmentDesign a support-escalation structure where resolving an issue always clears whichever one currently has the most open reports, breaking ties by the most recently reported occurrence. Tests combining frequency and recency so both operations run in O(1).
AmazonSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates knowledge of IPv4 addressing, CIDR subnet matching, and access-control rule resolution, assessing competency in bitwise address reasoning, prefix-length precedence, and rule tie-breaking.
AmazonSoftware EngineerCoding & AlgorithmsTechnical ScreenMerge two severity-labeled patch queues into one install order that keeps each queue's internal order, and return the minimum number of severity inversions over every valid merge. Tests DP over two sequences and efficient counting with letters as priorities.
AmazonSoftware EngineerCoding & AlgorithmsOnline AssessmentThis problem tests your ability to use the sliding window technique to find the longest contiguous subarray that satisfies a specific count-based constraint.
AmazonSoftware EngineerCoding & AlgorithmsOnline AssessmentThis problem tests string manipulation, hash set lookups, and the ability to efficiently identify compound words formed by the concatenation of exactly two distinct words from a provided collection.
AmazonSoftware EngineerCoding & AlgorithmsTechnical ScreenThis problem tests the ability to optimize sliding window calculations for extremely large arrays by leveraging compressed data structures (run-length encoding) rather than materializing the full array.
AmazonSoftware EngineerCoding & AlgorithmsOnline AssessmentThis problem tests your ability to detect cycles in a directed graph and perform a topological sort to resolve dependencies.
AmazonSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates understanding of directed graphs, dependency resolution and cycle detection, and the ability to reason about valid ordering constraints within a graph representation.
AmazonSoftware EngineerCoding & AlgorithmsOnline AssessmentThis question evaluates graph traversal and reachability reasoning on a 2D elevation grid, testing algorithmic problem-solving, complexity analysis, and handling of monotonic flow constraints.
AmazonSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates proficiency in string manipulation, efficient lookup structures (e.g., hashing/trie) and dynamic programming or recursion for word segmentation, testing algorithmic efficiency and data-structure selection within the Coding & Algorithms domain.
AmazonSoftware EngineerCoding & AlgorithmsTechnical ScreenFind first unique character 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.
AmazonSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates a candidate's proficiency in array and substring algorithm design, including concepts such as dynamic programming, hashing, and efficient search techniques.
AmazonSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates algorithmic problem-solving with arrays and complexity-aware design, testing skills in efficient subarray identification, boundary reasoning, and performance analysis within the Coding & Algorithms domain.
AmazonSoftware EngineerCoding & AlgorithmsOnline AssessmentThis question evaluates algorithmic design and array-processing skills, specifically reasoning about subarray endpoint vs interior relationships, range comparisons, and designing solutions with subquadratic time and space complexity.
AmazonSoftware EngineerCoding & AlgorithmsOnline AssessmentThis problem tests your ability to efficiently manage character frequency tracking while processing string prefixes, using hash maps or frequency arrays to validate partitioning conditions.
AmazonSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates algorithm design and combinatorial optimization skills, focusing on scheduling and load-balancing under per-center capacity constraints and frequency-based counting.
AmazonSoftware EngineerCoding & AlgorithmsOnline AssessmentThis question evaluates string-processing skills, combinatorial counting of substrings, simulation of time-based state changes, and algorithmic complexity analysis.
AmazonSoftware EngineerCoding & AlgorithmsOnline AssessmentThis problem tests your ability to determine the minimum total operations required to make an array non-decreasing by incrementing contiguous subarrays, requiring insights into difference arrays or monotonic properties.
AmazonSoftware EngineerCoding & AlgorithmsOnline AssessmentThis question evaluates skills in time-series data processing, timestamp parsing and time-zone normalization, scalable stream or batch handling for logs that exceed memory, algorithmic complexity analysis, and test-case design for edge conditions such as midnight boundaries and duplicate events.
AmazonSoftware EngineerCoding & AlgorithmsOnsiteThis question evaluates understanding of pathfinding in grid-based environments, graph traversal concepts, and algorithmic complexity when navigating obstacles and boundary constraints in an unweighted 2D search space.
AmazonApplied ScientistCoding & AlgorithmsOnsiteThis question evaluates array manipulation and algorithmic problem-solving skills, focusing on understanding how local subarray sorting affects global order, edge-case reasoning (already-sorted arrays, duplicates, strictly decreasing sequences), and complexity analysis within the Coding & Algorithms domain.
AmazonSoftware EngineerCoding & AlgorithmsTechnical ScreenThis question evaluates a candidate's ability to model string transformations as a graph, apply graph traversal and shortest-path reasoning, and manage efficient string-based search and data-structure choices within the Coding & Algorithms domain.
AmazonApplied ScientistCoding & AlgorithmsTechnical ScreenThis problem tests your ability to efficiently search through chronologically ordered records and handle binary search logic with custom comparison rules.
AmazonSoftware EngineerCoding & AlgorithmsOnsiteTests array traversal and hash table lookups to find a two-sum pair that minimizes the second index, running in linear time and space.
AmazonSoftware EngineerCoding & AlgorithmsTechnical ScreenFind any valid set of the k most frequent distinct integers, handling boundary ties with frequency counting, bounded heaps, or frequency buckets.
AmazonSoftware EngineerCoding & AlgorithmsOnline AssessmentGiven two nondecreasing integer arrays and a one-based integer k, return the k-th smallest value in their combined multiset. Work through the function contract, boundary cases, correctness argument, and time and space complexity expected in a production-quality solution.
AmazonSoftware EngineerCoding & AlgorithmsTechnical ScreenDeserialize a level-order serialized binary search tree and find its kth smallest element using an efficient in-order traversal.
AmazonSoftware EngineerCoding & AlgorithmsOnsiteFind the largest k for which at least k instance ratings are at least k, handling threshold equality and the zero-answer case.
AmazonSoftware EngineerCoding & AlgorithmsOnline AssessmentThis problem tests tree traversal techniques and recursive logic to identify the deepest node that is an ancestor to two specified nodes within a binary tree.
AmazonSoftware EngineerCoding & AlgorithmsTechnical Screen