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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.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 691–720 of 3276 results
- Capital OneMediumData ScientistExplain Shell Script Line-by-Line for Data Science Workflows
This question evaluates familiarity with shell scripting for reproducible data-science workflows, Python object-oriented design including transformer patterns (fit/transform separation), outlier detection and imputation strategies, code-style critique, and unit testing competency.
Coding & AlgorithmsTechnical Screen - Capital OneMediumData ScientistExplain Shell Script for Python Virtual Environment Setup
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Explain Shell Script for Python Virtual Environment Setup states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - Capital OneMediumSoftware EngineerFind Repeated-Value Patterns in a Matrix
Match a symbol pattern inside an integer matrix using per-window bijections, repeated values, distinct symbols, and ordered match coordinates.
Coding & AlgorithmsOnline Assessment - Capital OneMediumSoftware EngineerFind the First Array Element Smaller Than Both of Its Neighbors
A coding problem that asks for the first element of an integer array whose left and right neighbors are both strictly larger than it, returning -1 when no element qualifies. It tests careful boundary handling, strict comparisons when neighbors are equal, and precise output rules.
Coding & AlgorithmsOnline Assessment - Capital OneMediumSoftware EngineerFind the Row Watched by the Most Security Cameras
Each security camera covers a symmetric band of rows around its mounted position; find the integer row watched by the most cameras, breaking ties toward the smallest row number, using a sweep-line count instead of scanning every covered row.
Coding & AlgorithmsOnline Assessmentsweep-linesortingintervals - Capital OneMediumSoftware EngineerFind the Top-Left Submatrix Matching a Grid Pattern With Letter Variables
Locate a pattern grid inside an integer matrix, where each pattern cell is either an exact number or a letter that must stand for one consistent value, and return the top-left corner of the match with the lowest row and then the lowest column. It tests two-dimensional scanning, variable binding, and tie-breaking rules.
Coding & AlgorithmsOnline Assessment - Capital OneMediumData ScientistFix failing tests and refactor code
This question evaluates a candidate's ability to debug, test, and refactor Python code with attention to state management, mutable default arguments, deterministic unit testing, API design, and type-safety.
Coding & AlgorithmsTechnical Screen - Capital OneMediumSoftware EngineerGrid State After a Given Number of Days of Spoilage Spreading to Neighbors
A grid holds empty cells, fresh items and spoiled items, and each day spoilage spreads from every spoiled item to its edge-adjacent fresh neighbors. Given the grid and a number of days that may be very large, return the grid after exactly that many days. It tests simultaneous multi-source spreading, day-by-day timing, and unreachable cells.
Coding & AlgorithmsHR Screen - Capital OneMediumSoftware EngineerImplement 2D transforms and find max-lit point
This question evaluates array-manipulation and interval-analysis skills, specifically in-place 2D matrix transformations (row/column swaps, reversals, rotations) and determining the point with maximum overlap among one-dimensional illumination intervals.
Coding & AlgorithmsOnline Assessment - Capital OneMediumSoftware EngineerImplement deposit, withdraw, and transfer in a class
This question evaluates a candidate's competence in concurrent programming, atomic state updates, and class-level account management for basic monetary operations.
Coding & AlgorithmsOnsite - Capital OneMediumMachine Learning EngineerImplement string/matrix simulations and counting pairs
This problem tests string manipulation, simulation of grid-based gravitational collapse, and efficient combinatorial counting of string combinations.
Coding & AlgorithmsOnline AssessmentStringsSimulationHashing - Capital OneMediumMachine Learning EngineerMaximize grid-path expression and count sawtooth subarrays
This multi-part question evaluates dynamic programming and state management for constrained grid traversal with left-to-right expression evaluation, alongside parity-based array analysis and combinatorial counting of contiguous subarrays.
Coding & AlgorithmsHR Screen - Capital OneMediumData ScientistOptimize invites under capacity constraints
This question evaluates a candidate's competency in probabilistic expected-value optimization, algorithmic efficiency for large-scale inputs, and constrained combinatorial selection including grouped all-or-nothing decisions and cost modeling.
Coding & AlgorithmsOnsite - Capital OneMediumSoftware EngineerPlace Pieces on a Grid
This question evaluates spatial reasoning, matrix and array manipulation, collision detection, and stateful simulation skills required to implement ordered placement of shaped pieces on a grid.
Coding & AlgorithmsOnsite - Capital OneMediumData ScientistRefactor code and enforce robustness
This question evaluates proficiency in code refactoring, robustness, input validation, unit testing, environment specification, and complexity analysis for Python data-processing workflows (pandas), within the Coding & Algorithms domain for Data Scientist roles.
Coding & AlgorithmsOnsite - Capital OneMediumSoftware EngineerRemove nodes with a given value
This problem tests your ability to manipulate singly linked lists, specifically handling edge cases like removing head nodes and reassigning pointers in a single pass.
Coding & AlgorithmsTechnical ScreenLinked ListPointersRecursion - Capital OneHardSoftware EngineerReorder a String by Alternating Its Front and Back Characters
Rearrange a string by taking characters alternately from its front and its back: first, last, second, second-to-last and so on until every character is used once. Tests clean index handling for even and odd lengths and building the result efficiently for long inputs.
Coding & AlgorithmsOnline Assessment - Capital OneMediumSoftware EngineerReorder a String by Alternating Its Left and Right Ends
This problem tests string manipulation, two-pointer logic, and the ability to efficiently manage index traversal in both directions simultaneously.
Coding & AlgorithmsOnline AssessmentTwo PointersStringsAlgorithms - Capital OneMediumMachine Learning EngineerReturn all root-to-leaf tree paths
This question evaluates competence with binary tree structures, path enumeration and traversal techniques along with the ability to represent traversal results as formatted strings.
Coding & AlgorithmsOnsite - Capital OneMediumSoftware EngineerReturn the Top Two Teams by Points, Goal Difference, and Tie Breakers
Implement a ranking algorithm to evaluate sports competition matches, compute points, goal differential, and total goals for each team, and return the indices of the top two teams using multi-level tie-breakers.
Coding & AlgorithmsOnline AssessmentSortingHash TableArray - Capital OneEasyData ScientistReview Preprocessing Code and Tests
This problem tests your ability to identify common pitfalls in data science pipelines, specifically concerning data leakage, handling missing values, and software engineering best practices for reproducibility.
Coding & AlgorithmsOnsiteData PreprocessingData LeakageCode Review - Capital OneMediumMachine Learning EngineerRotate matrix and find max lamp coverage
This question evaluates array and matrix manipulation, in-place algorithm design, interval processing (sweep-line) and interval merging skills, testing competencies in algorithm design, complexity analysis, and robust edge-case reasoning within the Coding & Algorithms domain.
Coding & AlgorithmsOnline Assessment - Capital OneMediumSoftware EngineerSimulate Rot Spreading Through an Orchard Grid Over a Number of Days
A grid simulation question about an orchard of rotten trees, healthy trees and empty ground, where each day rot spreads at once from every rotten tree to the healthy trees directly beside it. It asks for the orchard after a given number of days and tests simultaneous updates, blocked cells and very large day counts.
Coding & AlgorithmsOnline Assessment - Capital OneMediumSoftware EngineerSimulate a Bank Ledger With Validated Transfers, Deposits and Withdrawals
A coding exercise that simulates a bank's in-memory ledger: apply an ordered sequence of transfers, deposits and withdrawals across numbered accounts and report which requests succeed. It tests careful validation of account numbers and balances, ordered state updates, and 64-bit arithmetic.
Coding & AlgorithmsOther - Capital OneMediumMachine Learning EngineerSimulate round-robin package assignment to servers
This problem tests array indexing manipulation and logic for stateful resource allocation, specifically handling circular queues with dynamic availability constraints.
Coding & AlgorithmsOnline AssessmentArraysSimulationQueueing - Capital OneMediumMachine Learning EngineerSolve Four Coding Assessment Tasks
This multi-part coding question evaluates array manipulation, algorithm simulation, deterministic spatial placement, and constrained optimization competencies across tasks involving cumulative thresholds, iterative subtraction sequences, fixed-shape grid placement, and minimal-increment adjustments for monotonic patterns.
Coding & AlgorithmsOnline Assessment - Capital OneEasyMachine Learning EngineerSolve OA tasks on string, grid path, subarrays
This problem tests proficiency in string manipulation, grid traversal with condition-based movement, and linear-time subarray analysis.
Coding & AlgorithmsOnline AssessmentArraysDynamic ProgrammingGrid Traversal - Capital OneMediumSoftware EngineerSolve four algorithmic coding tasks
This multi-part question evaluates algorithmic problem-solving across frequency counting (equal-value pairs), simulation and in-place grid transformation (match-three gravity), matrix diagonal pattern checking, and interval/range data-structure management, emphasizing correctness under constraints and rigorous time/space complexity reasoning.
Coding & AlgorithmsOnline Assessment - Capital OneHardSoftware EngineerSolve multiple algorithmic interview questions
This multi-part prompt evaluates algorithmic problem-solving and core data-structure competencies such as array manipulation, modular/date arithmetic, matrix transformations, dynamic set and interval maintenance, string concatenation frequency counting, and path-based expression evaluation on grids.
Coding & AlgorithmsOnline Assessment - Capital OneMediumSoftware EngineerSort Each Adjacent Pair of an Array, Leaving an Odd Last Element in Place
Given an integer array, put each consecutive pair of elements in ascending order while keeping every pair in its original place, and leave the final element untouched when the length is odd. Tests precise reading of a short specification and careful index handling.
Coding & AlgorithmsOnline Assessment
Capital One