#bitmask

5 bitmask interview questions, asked at Meta, Airbnb, Amazon and 1 more company. Last asked Sep 2026.

Grid maze solver with keys, doors and bombs, AI-assistedCodingYou get a small existing codebase that models a grid maze and an AI assistant you may use. Fix a bug in the provided code, then find the shortest path from start to exit, then add…
Last asked Sep 2026
Choose words with no shared letters to cover the most lettersCodingGiven a list of lowercase words, pick a subset in which no letter appears twice across the chosen words, maximizing the number of distinct letters covered. Start with a correct…
Last asked Aug 2026
Palindromic paths from a node to the rootCodingA storage system keeps its directories in a tree. Each directory holds one lowercase letter as a label. You are given: - arr: a list of n lowercase letters; arri is the label of…
Last asked May 2026
Fewest conflicts when merging branchesCodingSeveral branches have to be merged, and the order of the merges changes how many commit conflicts come up. Given the branches and how conflicts arise between them, return the…
Last asked Jan 2026
Shortest path to collect all keysCodingA grid has walls, a start cell, keys (lowercase letters) and locks (the matching uppercase letters). A lock can only be passed once you hold its key. Return the fewest steps to…
Last asked Aug 2025