Interview questions
Find a company or topic. Read the sources, then practice.
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Showing 451–475
Given a binary matrix where each row is sorted non-decreasing (all 0s before 1s) and you can only query entries via a provided API, find…
Companies: Uber
Array · Binary Search · Interactive · Matrix
Last reported Jun 2026
Build a concurrent restaurant booking system that handles simultaneous reservation requests. The system should manage table availability, prevent double-bookings, and ensure…
Companies: Revolut
Last reported Jun 2026
Given an integer array, return the maximum product obtainable by multiplying any three numbers. Consider both the three largest values and the combination of the…
Companies: Salesforce
Array · Math · Sorting
Last reported Jun 2026
Compute the sum over all contiguous subarrays of (minimum element × sum of elements), which requires attributing each element’s contribution when it is the subarray…
Companies: Amazon
Last reported Jun 2026
Given a string s, find the minimum number of character deletions required so that no two different characters have the same (nonzero) frequency. This reduces…
Companies: Freshworks, Microsoft
Last reported Jun 2026
Given nums1 as a subset of nums2, for each element in nums1 return the first greater element that appears to its right in nums2 (or…
Companies: Flipkart, Microsoft
Array · Hash Table · Monotonic Stack · Stack
Last reported Jun 2026
Design a stack data structure that supports standard push, pop, and top operations while also allowing retrieval of the minimum element in constant time (O(1)).
Companies: Expedia
Last reported Jun 2026
Companies: OpenAI
Simulation & State Machines
Last reported Jun 2026
Given a list representing a stack trace with function calls and returns (indicated by '->' and '<-'), find the function call path that occurs most…
Companies: Roblox
Last reported Jun 2026
Given a binary grid, count how many distinct island shapes (connected components of 1s via 4-directional adjacency) appear, treating two islands as identical if they…
Companies: Anduril, Oracle, TikTok
Array · Breadth-First Search · Depth-First Search · Hash Function
Last reported Jun 2026
Given a set of axis-aligned rectangles, compute the total area covered by them without double-counting overlaps; the core challenge is correctly handling overlapping regions…
Companies: Microsoft
Last reported Jun 2026
Find the minimum number of moves from the start to collect all keys in a grid containing walls and locks (locks are passable only if…
Companies: Microsoft
Last reported Jun 2026
Given a collection of block types each defined by a count, weight, and maximum supported weight, determine the maximum number of blocks that can be…
Companies: LinkedIn
Last reported Jun 2026
Design a data structure supporting addWord(word) and search(pattern) where '.' in the pattern matches any single letter; the core challenge is efficient pattern matching with…
Companies: Google, Microsoft
Last reported Jun 2026
Given an array and integer k, maximize the number of disjoint pairs whose elements sum to k — a frequency/ complement-matching problem (can be solved…
Companies: NVIDIA
Last reported Jun 2026
Check if the entire string s matches pattern p where '?' matches any single character and '*' matches any sequence (including empty). The core challenge…
Companies: Meta, Microsoft
Last reported Jun 2026
Determine whether a string of 'a', 'b', 'c' can be formed from an empty string by repeatedly inserting the substring "abc" (equivalently, whether s can…
Companies: Google
Last reported Jun 2026
Companies: OpenAI
Dynamic Programming · Grids & Matrices
Last reported Jun 2026
Given a string, generate all possible subsequences by deleting zero or more characters while keeping the original order of remaining characters. Return the list of…
Companies: Expedia
Last reported Jun 2026
Given a list of escape room participants and their completion times, implement a leaderboard system that ranks players based on their performance. The solution should…
Companies: Pinterest
Last reported Jun 2026
Control a robot with only move/turn/clean APIs to traverse and clean every reachable cell in an unknown grid with obstacles and no global map. The…
Companies: Google, LinkedIn, Meta, Waymo
Backtracking · Interactive
Last reported Jun 2026