Interview questions
Find a company or topic. Read the sources, then practice.
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Find a company or topic. Read the sources, then practice.
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Showing 51–75
Fill the 9x9 Sudoku board by replacing '.' so each digit 1–9 appears exactly once in every row, column, and 3x3 sub-box. This is a…
Companies: Confluent
Last reported Oct 2026
Determine whether a password is "strong" by verifying it has length >= 8, contains at least one lowercase letter, one uppercase letter, one digit, and…
Companies: Grab
Last reported Oct 2026
Design a system to track delivery drivers and compute their earnings based on hourly rates and trip durations. Implement APIs to add drivers, record trips…
Companies: Rippling
Last reported Oct 2026
Build a pipeline to apply JSON-defined transformations to 10k images, then optimize for performance using concurrency and design for distributed processing at million-image…
Companies: Anthropic
Last reported Oct 2026
Design and implement an in-memory key-value store that supports basic operations (get, put, delete) with automatic key expiration based on TTL (time-to-live). The…
Companies: Airbnb, Geminus Tech, Netflix, NVIDIA
Last reported Oct 2026
Ingest a publicly available "dump" file and return the sorted occurrences of a given string of text.
Companies: Apple
Last reported Oct 2026
Implement an LZ78-style dictionary compression algorithm that encodes a string into compressed mapping tuples. Using the generated dictionary, decompress the encoded tuples…
Companies: LinkedIn
Last reported Oct 2026
Given a functional directed graph (each node has at most one outgoing edge), return the length of the longest directed cycle or -1 if no…
Companies: Anduril
Breadth-First Search · Depth-First Search · Graph Theory · Kosaraju's Algorithm
Last reported Oct 2026
Given up to 100 points and a fixed radius r, find where to place a circle of radius r to cover the maximum number of…
Companies: Anduril, Meta
Last reported Oct 2026
Parse a chemical formula with multi-letter element names, numeric multipliers, and nested parentheses to compute the total count of each atom, correctly propagating multipliers…
Companies: Agoda
Last reported Oct 2026
Implement a data structure that supports the following operations, all in O(1) time complexity: - get(key): Returns the value associated with the given key. -…
Companies: Cisco, Microsoft
Last reported Oct 2026
Parse a string representing nested integers and lists (e.g., "324" or "[123,[456,[789]]") and reconstruct the corresponding NestedInteger object, correctly handling brackets…
Companies: Moveworks
Last reported Oct 2026
Companies: OpenAI
Dynamic Programming
Last reported Oct 2026
Design a system that tracks user token credits and can efficiently query the number of tokens a user has at any given timestamp. The service…
Companies: OpenAI
Last reported Oct 2026
Companies: OpenAI
Graphs
Last reported Oct 2026
Companies: OpenAI
Simulation & State Machines
Last reported Oct 2026
Given a DAG of course prerequisites where each course has a duration and any number of courses can run in parallel once prerequisites are satisfied…
Companies: Google, Meta, Modular, Salesforce +1
Array · Directed Acyclic Graph · Dynamic Programming · Graph Theory
Last reported Oct 2026
Determine whether there's a 4-directional path from the top-left to bottom-right of an m×n binary grid such that the number of unsafe cells (grid[i][j]==1) encountered…
Companies: Amazon
Last reported Oct 2026
Given an m x n matrix where each row and each column is sorted in ascending order, determine whether a target value exists by exploiting…
Companies: Amazon, Goldman Sachs
Array · Binary Search · Divide and Conquer · Matrix
Last reported Oct 2026
Companies: OpenAI
Graphs
Last reported Oct 2026
Evaluate a valid arithmetic expression string containing non-negative integers and the operators +, -, *, / (with spaces allowed), where division truncates toward zero. The…
Companies: Anduril, Flex, Meta, Snap +1
Math · Stack · String
Last reported Oct 2026
Find the minimum-cost route from src to dst in a directed weighted graph with the constraint of at most k stops (i.e., a bound on…
Companies: Flipkart, Illumio, Meta, Oracle +1
Breadth-First Search · Depth-First Search · Dynamic Programming · Graph Theory
Last reported Oct 2026
Build a command-line interface tool that allows field technicians to reboot remote servers via REST API calls. Implement basic functionality, error handling, concurrent…
Companies: CoreWeave
Last reported Oct 2026
Given coin denominations available in unlimited quantity and a target amount, find the minimum number of coins needed to form that amount (return -1 if…
Companies: Amazon, Google, Pinterest, Uber
Array · Breadth-First Search · Complete Knapsack · Dynamic Programming
Last reported Oct 2026
Given courses as nodes and prerequisite pairs as directed edges, determine whether the directed graph is acyclic — return true if a topological ordering exists…
Companies: Amazon, Anduril, Cloudflare, DoorDash +6
Breadth-First Search · Depth-First Search · Directed Acyclic Graph · Graph Theory
Last reported Oct 2026