Interview questions

Rotate Array

Rotate an integer array to the right by k steps (k may exceed the array length), effectively moving each element to index (i+k) mod n…

Companies: Apple, Microsoft, Nutanix, TikTok

Array · Math · Two Pointers

Last reported Jun 2026

Valid Palindrome

Check whether a string becomes a palindrome after lowercasing and removing all non-alphanumeric characters. The typical challenge is to do this efficiently (O(n)) by scanning…

Companies: Apple, Bloomberg, Meta

String · Two Pointers

Last reported Jun 2026

Word Search II

Given an m×n letter grid and a list of words, find all words that can be formed by sequentially adjacent (horizontal/vertical) non-repeating cells. The core…

Companies: Amazon, Bloomberg, Glean, Google +2

Array · Backtracking · Matrix · String

Last reported Jun 2026

Non-decreasing Subsequences

Return all distinct non-decreasing subsequences (length ≥ 2) from an integer array — generate subsequences in index order using DFS/backtracking while avoiding duplicate…

Companies: Microsoft

Last reported May 2026

Reverse Nodes in k-Group

Given the head of a linked list and an integer k, reverse the nodes of the list k at a time and return the modified…

Companies: Adobe, Microsoft, TikTok

Linked List · Recursion

Last reported May 2026

Split a Circular Linked List

Companies: Microsoft

Last reported May 2026

Find Pairs with the Smallest Difference

Given an array of integers, find and print all pairs of numbers that have the smallest difference between them, returning the results in increasing order…

Companies: Microsoft

Last reported May 2026

Length of the Longest Subsequence That Sums to Target

Find the maximum length subsequence of positive integers that sums exactly to target (or return -1 if none exists). This is a 0/1 knapsack–style problem…

Companies: Booze Allen Hamilton

Last reported May 2026

Construct Quad Tree

Given an n×n binary grid (n a power of two), recursively build a quadtree by subdividing the grid into four equal quadrants until each region…

Companies: Snowflake, Uber

Array · Divide and Conquer · Matrix · Tree

Last reported May 2026

Math Interpreter with Function Definitions

Implement a math interpreter that processes a list of string commands acting on a single global integer x (initially 0). Commands are: ADD k (add…

Companies: Snowflake

Last reported May 2026

Maximum Good Subarray Sum

Find a contiguous subarray whose first and last elements differ by exactly k and return the maximum possible subarray sum (or 0 if none). With…

Companies: Meta

Last reported May 2026

Next Palindrome Using Same Digits

Given a number, rearrange its digits to form the smallest palindrome strictly greater than the original using exactly the same digits (or report impossible). The…

Companies: Uber

Last reported May 2026

Palindrome Linked List

Companies: eBay, Meta, Microsoft

Linked List · Recursion · Stack · Two Pointers

Last reported May 2026

Reverse Integer

Reverse the digits of a signed 32-bit integer, preserving the sign, and return the reversed number or 0 if reversing would overflow the 32-bit signed…

Companies: Bloomberg, eBay, Google, Meta +2

Math

Last reported May 2026

Search Suggestions System

For each prefix formed by typing characters of a search word, return up to three lexicographically smallest products from a given list that share that…

Companies: eBay, Meta, Miro

Last reported May 2026

Path With Maximum Minimum Value

Given an integer grid where you can move 4-directionally from the top-left to the bottom-right, find a path that maximizes the minimum cell value along…

Companies: Google

Last reported May 2026

Maximum Severity of Drug Interactions

Given a list of drugs a patient is taking and a dictionary of known drug interactions with severity levels, determine which drugs interact with one…

Companies: Ro

Last reported May 2026

Remove Duplicates from Sorted Array

Given a sorted array, remove duplicates in-place so each unique value appears only once (preserving order) and return the count k of unique elements. This…

Companies: Bloomberg, Google, Meta, Microsoft

Array · Two Pointers

Last reported May 2026

Set Matrix Zeroes

Given an m×n matrix, set every row and column to zero wherever an element is zero, modifying the matrix in-place. The key challenge is to…

Companies: Meta, Microsoft

Last reported May 2026

Compute Plant Infection Time

Companies: OpenAI

Last reported May 2026

Implement a Banking System

Companies: Anthropic

Data Structure Design · Payments & Ledgers

Last reported May 2026

Calculate Amount Paid in Taxes

Given sorted tax brackets with upper bounds and percentages, compute the progressive tax on a given income by summing, for each bracket in order, the…

Companies: Bloomberg, Gusto, Snowflake

Array · Simulation

Last reported May 2026