Airbnb Coding Interview Questions

Text Justification

Given an array of strings words and a width maxWidth, format the text such that each line has exactly maxWidth characters and is fully (left and right) justifie...

Maximum Profit in Job Scheduling

We have n jobs, where every job is scheduled to be done from startTime[i] to endTime[i], obtaining a profit of profit[i].

Palindrome Pairs

You are given a 0-indexed array of unique strings words.

Combination Sum

Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum...

Trapping Rain Water

Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it can trap after raining.

Cheapest Flights Within K Stops

There are n cities connected by some number of flights. You are given an array flights where flights[i] = [fromi, toi, pricei] indicates that there is a flight...

Sliding Puzzle

On an 2 x 3 board, there are five tiles labeled from 1 to 5, and an empty square represented by 0. A move consists of choosing 0 and a 4-directionally adjacent...

Shortest Path to Get All Keys

You are given an m x n grid grid where:

Minimum Window Substring

Given two strings s and t of lengths m and n respectively, return the minimum window substring of s such that every character in t (including duplicates) is inc...

Simple Bank System

You have been tasked with writing a program for a popular bank that will automate all its incoming transactions (transfer, deposit, and withdraw). The bank has...

Two Sum

Given an array of integers nums and an integer target, return the indices of the two numbers that add up to target.

Add Two Numbers

You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each of their nodes contains a sing...

Basic Calculator II

Given a string s which represents an expression, evaluate this expression and return its value.

Intersection of Two Linked Lists

Given the heads of two singly linked-lists headA and headB, return the node at which the two lists intersect. If the two linked lists have no intersection at al...

Word Search II

Given an m x n board of characters and a list of strings words, return all words on the board.

Maximum Candies You Can Get from Boxes

You have n boxes labeled from 0 to n - 1. You are given four arrays: status, candies, keys, and containedBoxes where:

Contains Duplicate II

Given an integer array nums and an integer k, return true if there are two distinct indices i and j in the array such that nums[i] == nums[j] and abs(i - j) <=...

Merge k Sorted Lists

You are given an array of k linked-lists lists, each linked-list is sorted in ascending order.

Contains Duplicate

Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct.

Pyramid Transition Matrix

You are stacking blocks to form a pyramid. Each block has a color, which is represented by a single letter. Each row of blocks contains one less block than the...

Minimum Number of Vertices to Reach All Nodes

Given a directed acyclic graph, with n vertices numbered from 0 to n-1, and an array edges where edges[i] = [fromi, toi] represents a directed edge from node fr...

Robot Bounded In Circle

On an infinite plane, a robot initially stands at (0, 0) and faces north. Note that:

Add Strings

Given two non-negative integers, num1 and num2 represented as string, return the sum of num1 and num2 as a string.

Minimum Number of Flips to Convert Binary Matrix to Zero Matrix

Given a m x n binary matrix mat. In one step, you can choose one cell and flip it and all the four neighbors of it if they exist (Flip is changing 1 to 0 and 0...

Convert to Base -2

Given an integer n, return a binary string representing its representation in base -2.

Single Number

Given a non-empty array of integers nums, every element appears twice except for one. Find that single one.

Reverse Bits

Reverse bits of a given 32 bits signed integer.

Contains Duplicate III

You are given an integer array nums and two integers indexDiff and valueDiff.

Maximal Square

Given an m x n binary matrix filled with 0's and 1's, find the largest square containing only 1's and return its area.

Convert Sorted Array to Binary Search Tree

Given an integer array nums where the elements are sorted in ascending order, convert it to a height-balanced binary search tree.

House Robber

You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping you from rob...

Valid Parentheses

Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

Happy Number

Write an algorithm to determine if a number n is happy.

Mini Parser

Given a string s represents the serialization of a nested list, implement a parser to deserialize it and return the deserialized NestedInteger.

Regular Expression Matching

Given an input string s and a pattern p, implement regular expression matching with support for '.' and '' where:

Subarray Product Less Than K

Given an array of integers nums and an integer k, return the number of contiguous subarrays where the product of all the elements in the subarray is strictly le...

Shortest Uncommon Substring in an Array

You are given an array arr of size n consisting of non-empty strings.

All O`one Data Structure

Design a data structure to store the strings' count with the ability to return the strings with minimum and maximum counts.

Fraction to Recurring Decimal

Given two integers representing the numerator and denominator of a fraction, return the fraction in string format.

Merge Intervals

Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals, and return an array of the non-overlapping intervals that cove...

Time Based Key-Value Store

Design a time-based key-value data structure that can store multiple values for the same key at different time stamps and retrieve the key's value at a certain...

Shortest Path in Binary Matrix

Given an n x n binary matrix grid, return the length of the shortest clear path in the matrix. If there is no clear path, return -1.

Coin Change

You are given an integer array coins representing coins of different denominations and an integer amount representing a total amount of money.

Making A Large Island

You are given an n x n binary matrix grid. You are allowed to change at most one 0 to be 1.

Can Place Flowers

You have a long flowerbed in which some of the plots are planted, and some are not. However, flowers cannot be planted in adjacent plots.

Flatten Nested List Iterator

You are given a nested list of integers nestedList. Each element is either an integer or a list whose elements may also be integers or other lists. Implement an...