Interview questions

Rectangle Area

Given coordinates of two axis-aligned rectangles, compute the total area covered by both. The key is to sum their individual areas and subtract the area…

Companies: General Motors, Google

Last reported Aug 2026

The Skyline Problem

Given a list of rectangular buildings [left, right, height], compute the skyline as the sequence of key points where the maximum building height changes across…

Companies: Amazon, General Motors, Pinterest

Last reported Aug 2026

Binary Tree Tilt

Compute the sum of every node's tilt in a binary tree, where a node's tilt is the absolute difference between the sum of values in…

Companies: Microsoft

Last reported Aug 2026

Majority Element

Given an array of n integers, return the element that appears more than ⌊n/2⌋ times (the majority element is guaranteed to exist). The goal is…

Companies: Amazon, Bloomberg, Coupang, Google +1

Array · Boyer–Moore Majority Vote Algorithm · Counting · Divide and Conquer

Last reported Aug 2026

Shortest Distance from All Buildings

Given a grid with buildings (1), empty land (0), and obstacles (2), find an empty cell that minimizes the sum of shortest (Manhattan) path distances…

Companies: Amazon, Coupang, DoorDash, Goldman Sachs +2

Array · Breadth-First Search · Matrix

Last reported Aug 2026

Two Sum

Given an array of integers and a target, return the indices of two distinct elements whose values sum to the target (exactly one valid solution…

Companies: Amazon, Apple, Bloomberg, Brex +13

Array · Hash Table

Last reported Aug 2026

Simulate Infection Spread with Immunity and Recovery

Implement an infection simulation on a grid. Extend the simulation with immune cells and a recovery countdown for each affected cell.

Companies: OpenAI

Grid Traversal · Simulation · Simulation & State Machines · State Machines

Last reported Aug 2026

Maximum Number of Occurrences of a Substring

Find the substring (overlaps allowed) that occurs most often in s among those with length between minSize and maxSize and at most maxLetters distinct characters…

Companies: Chewy, LinkedIn, Microsoft

Hash Table · Sliding Window · String

Last reported Aug 2026

Create a License Plate Generator

Create a function that generates a license plate based on specific rules and formats. The function should take input parameters such as the number of…

Companies: Google

Last reported Aug 2026

Number of Provinces

Given an n x n symmetric adjacency matrix where isConnected[i][j]=1 denotes a direct undirected edge between cities, count the number of connected components (provinces) formed…

Companies: Amazon, Coupang, Uber

Breadth-First Search · Depth-First Search · Graph Theory · Union-Find

Last reported Aug 2026

Count Distinct Ways to Cross a River with Jumps of Up to 3

A fox needs to cross a river by jumping on logs, with the ability to jump up to 3 logs at a time. Determine the…

Companies: Agoda

Last reported Aug 2026

Find K Closest Elements

Given a sorted integer array and a target value x, return the k integers closest to x in ascending order. Ties are broken by preferring…

Companies: Asana, Meta, Microsoft

Last reported Aug 2026

K Closest Points to Origin

Given N points on the plane and an integer k, return the k points with the smallest Euclidean distance to the origin (order doesn't matter)…

Companies: Airbnb, Amazon, Asana, Meta

Array · Divide and Conquer · Geometry · Heap (Priority Queue)

Last reported Aug 2026

Log File Parser

Given a set of filter parameters and a collection of log lines, implement a parser that matches log entries against the provided filters. Return all…

Companies: Datadog

Last reported Aug 2026

The Earliest Moment When Everyone Become Friends

Given timestamped friendship events among N people, determine the earliest time when the social graph becomes fully connected; process events in chronological order and use…

Companies: Amazon, Google, Uber

Array · Sorting · Union-Find

Last reported Aug 2026

Web Crawler

Companies: Monzo, Opendoor, Ramp

Last reported Aug 2026

API Rate Limiter

Implement a rate limiting algorithm that accepts a unique key, a time period in seconds, and a maximum call count, and determines whether additional calls…

Companies: Bloomberg, Intuit, Microsoft, MongoDB

Last reported Aug 2026

Configuration File Merger

Given a master directory path, use helper functions to retrieve and merge multiple JSON-like configuration files, where more specific configurations can override default…

Companies: Yelp

Last reported Aug 2026

Top 5 Most Accessed Files Per Hour from Access Logs

Given an array of file access logs, calculate how frequently each file was accessed during each hour of the day. Use this data to determine…

Companies: Yelp

Last reported Aug 2026

Combination Sum II

Given a multiset of candidate numbers, return all unique combinations that sum to the target where each candidate may be used at most once. This…

Companies: Expedia, LinkedIn, Meta, Microsoft +1

Last reported Aug 2026

Design Underground System

Design a system that records passenger check-ins and check-outs and returns the average direct travel time between two stations. The core challenge is maintaining active…

Companies: Apple, Axon, Bloomberg, Ramp

Last reported Aug 2026

Matrix Multiplication

Given two matrices stored in binary files, implement matrix multiplication without using built-in functions by manually computing each output value using the row-by-column dot…

Companies: Intuit

Last reported Aug 2026