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Coding & Algorithms Interview Questions
Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.
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Showing 2221–2250 of 3276 results
- OtherHardSoftware EngineerImplement a multi-button click detector
This question evaluates competency in real-time event stream processing, per-button state management, and timing-based classification of input events such as distinguishing single versus long presses.
Coding & AlgorithmsTechnical Screen - OtherMediumData ScientistImplement multiplication without using the multiplication operator
This question evaluates proficiency in bitwise arithmetic, integer overflow semantics, sign handling, and algorithmic efficiency for implementing multiplication without using multiplication or division operators.
Coding & AlgorithmsTechnical Screen - OtherEasySoftware EngineerLowest Common Ancestor in an Explicit Binary Tree
Find the lowest common ancestor in a binary tree using explicit child arrays, including identical targets, ancestor targets, and deep trees.
Coding & AlgorithmsOnline Assessment - OtherMediumData ScientistProve reservoir sampling correctness
This question evaluates randomized and streaming algorithm skills, including mastery of reservoir sampling, induction-based correctness proofs, probability reasoning, and complexity analysis for sampling under strict memory constraints.
Coding & AlgorithmsOnsite - OtherMediumSoftware EngineerReturn the k-th row of Pascal-like triangle
This question evaluates combinatorics, array manipulation, and space-efficient algorithm design by requiring computation of a specific row of Pascal’s triangle without constructing the full triangle.
Coding & AlgorithmsOnline Assessment - OtherMediumSoftware EngineerSpreadsheet Formulas, Dependencies, and Circular References
Implement spreadsheet formulas with dependency updates, repeated references, unset cells, and cycle detection that recovers after formulas change.
Coding & AlgorithmsOther - OtherEasySoftware EngineerTrack Workers, Sessions, Promotions, and Bonus Pay
Implement worker sessions, current metadata, promotions, ordered filtering, and time-clipped compensation with historical rates and non-stacking double-pay intervals.
Coding & AlgorithmsOnline Assessment - OtherEasySoftware EngineerValidate Nested Parentheses, Brackets, and Braces
Validate nested parentheses, brackets, and braces with correct handling of empty input, mismatched closing symbols, and unfinished groups.
Coding & AlgorithmsOnline Assessment - OtherMediumData ScientistWrite mini-batch gradient descent
This question evaluates understanding and implementation of optimization algorithms for machine learning, specifically mini-batch gradient descent, and measures competency in numerical optimization, algorithmic implementation, and training dynamics within the Coding & Algorithms domain for Data Scientist roles.
Coding & AlgorithmsOnsite - OthersEasyData ScientistAnswer ancestor-walk queries on a rooted tree
This question evaluates understanding of tree data structures and ancestor-walk queries, assessing competency in traversing rooted trees, interpreting parent arrays, and designing efficient query-processing methods for large n and q.
Coding & AlgorithmsOnline Assessment - OthersMediumSoftware EngineerAnswer k-step ancestor queries in a rooted tree
This problem tests your ability to optimize ancestor lookups in a tree using the Binary Lifting technique to achieve logarithmic query time.
Coding & AlgorithmsOnline AssessmentTreesBinary LiftingDynamic Programming - Otter.AiMediumSoftware EngineerEvaluate Arithmetic Expressions
This problem tests your ability to parse and evaluate a string representing a mathematical expression with basic operator precedence, typically requiring a stack-based approach or a recursive descent parser.
Coding & AlgorithmsTechnical ScreenStackString ParsingMath - Otter.AiMediumSoftware EngineerFewest Adjacent-GCD Operations to Turn Every Array Element into 1
Given an array of positive integers, find the fewest operations that make every element 1, where each operation replaces one of two neighboring values with their greatest common divisor, or return -1 if it cannot be done. Tests GCD properties, lower-bound reasoning and careful case analysis on small arrays.
Coding & AlgorithmsOnsite - Otter.AiMediumSoftware EngineerFixed-Width Text Display
This question tests a candidate's ability to implement greedy line-packing and space-distribution algorithms, core string manipulation skills evaluated in software engineering interviews. It assesses practical application of text layout logic, including handling edge cases like single-word lines and justified formatting with uneven space distribution.
Coding & AlgorithmsTechnical Screen - Otter.AiMediumSoftware EngineerImplement an Arithmetic Expression Evaluator
This problem tests your ability to parse and evaluate mathematical expressions containing non-negative integers, addition, subtraction, multiplication, and nested parentheses using a stack-based approach or recursion.
Coding & AlgorithmsTechnical ScreenStackParsingMath - Otter.AiMediumSoftware EngineerIn-Memory Key-Value Store with Nested Transactions
This problem tests the ability to implement a nested transactional key-value store using stack-based state management and scope shadowing.
Coding & AlgorithmsTechnical ScreenHash MapStackTransactions - Otter.AiEasySoftware EngineerValidate Password Against Multiple Rules
This problem tests your ability to efficiently iterate through a string while maintaining multiple state-based flags to satisfy diverse validation criteria.
Coding & AlgorithmsTechnical ScreenStringsValidationAlgorithms - OuraMediumSoftware EngineerImplement Server Number Allocation
This problem tests your ability to manage and reuse resources efficiently using data structures that allow for logarithmic time allocation and deallocation within partitioned namespaces.
Coding & AlgorithmsOnline AssessmentData StructuresHeapHash Map - PDT PartnersMediumMachine Learning EngineerList All Positive Divisors of an Integer in Ascending Order, Then Beat Square-Root Time
Given a positive integer up to one trillion, return every positive divisor in ascending order, each listed once. The task tests divisor enumeration, correct handling of perfect squares and 64-bit values, and a follow-up asking whether the running time can grow more slowly than the square root of n.
Coding & AlgorithmsTechnical Screen - PalantirMediumSoftware EngineerApply Item Coupons with Exact Per-Item Cent Rounding
Implement a checkout calculation engine that applies item-specific coupons to cart lines using exact banker's rounding (round-half-to-even) per unit and returns the final cart total in integer cents.
Coding & AlgorithmsOnline AssessmentSimulationData StructuresMath - PalantirEasySoftware EngineerFind Shortest Paths in Road Network
This question evaluates understanding of graph data structures and shortest-path concepts, including correct modeling of undirected edges, unweighted versus weighted pathfinding, and algorithmic time and space complexity.
Coding & AlgorithmsOnsite - PalantirMediumSoftware EngineerGroup employees by shared interests
This question evaluates a candidate's competency in organizing and querying collections, mapping relationships between entities, and reasoning about algorithmic time and space complexity within data structures and grouping operations.
Coding & AlgorithmsTechnical Screen - PalantirEasySoftware EngineerMerge K Individually Sorted Integer Arrays Into One Sorted Array
Merge k integer arrays, each sorted in non-decreasing order, into one sorted array that keeps every duplicate. The interviewer asked for the two-pointer method and divide and conquer, so the problem tests merging sorted sequences and how the cost grows with the number of arrays.
Coding & AlgorithmsTechnical Screen - PalantirMediumSoftware EngineerSimulate a Growing Snake on a Grid and Report the Score After Every Move
Simulate a snake moving on a rectangular grid, eating food that appears one piece at a time, and return the score after every move or -1 once the snake leaves the board or runs into itself. It tests precise state simulation, collision rules around the moving tail, and efficient tracking of the snake's body.
Coding & AlgorithmsTechnical Screen - PalantirMediumSoftware EngineerStack Item and Category Coupons with an Eighty-Percent Cap
Implement a cart checkout calculator that stacks item and category discounts multiplicatively, caps savings at 80%, and applies round-half-up once per item.
Coding & AlgorithmsOnline AssessmentImplementationMathSimulation - Palo Alto NetworksMediumSoftware EngineerFind Maximum Rectangle in Bar Chart
This question evaluates algorithmic problem-solving and data structure proficiency in computing the maximum rectangular area within a histogram-like array, focusing on contiguous segment analysis and range-based aggregation.
Coding & AlgorithmsOnsite - Palo Alto NetworksMediumSoftware EngineerFind minimum tanks to cover all houses
This question evaluates a candidate's proficiency in algorithm design, specifically greedy strategies and string/array manipulation for coverage and optimization under local adjacency constraints.
Coding & AlgorithmsTechnical Screen - Palo Alto NetworksMediumSoftware EngineerFind normalized list difference efficiently
This question evaluates competency in computing normalized list differences, including string normalization, collection comparison, duplicate handling, and time and space complexity reasoning.
Coding & AlgorithmsOnsite - Palo Alto NetworksMediumSoftware EngineerMirror a binary tree and analyze complexity
This question evaluates understanding of binary tree manipulation and traversal methods, emphasizing recursion and iterative approaches as well as the ability to reason about time and space complexity.
Coding & AlgorithmsOnsite - ParadromicsMediumSoftware EngineerCompute ways to climb n steps
This Coding & Algorithms question evaluates recursion and dynamic programming concepts by asking for the count of distinct ways to climb n steps, framed at an algorithmic/implementation level. It is commonly asked because it probes recognition of overlapping subproblems and the ability to optimize naive recursive approaches through subproblem reuse and improved time/space efficiency.
Coding & AlgorithmsTechnical Screen
Otter.Ai
Palantir
Palo Alto Networks