Interview questions
Find a company or topic. Read the sources, then practice.
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Showing 1–19
Implement an LFU cache with O(1) average-time get and put operations that evicts the least-frequently-used key when capacity is exceeded, breaking ties by least-recently-used…
Companies: Amazon, Apple, Cisco, Goldman Sachs +3
Design · Doubly-Linked List · Hash Table · Linked List
Last reported Nov 2026
Implement an LRUCache that supports O(1) average-time get(key) returning the value or -1 and put(key, value) which inserts or updates a key and, if capacity…
Companies: Adobe, Amazon, Anthropic, Apple +29
Data Structure Design · Design · Doubly-Linked List · Hash Table
Last reported Oct 2026
Design a data structure that supports incrementing and decrementing string counts (removing keys when their count drops to zero) and can return any key with…
Companies: Atlassian, LinkedIn, Meta, Microsoft +2
Design · Doubly-Linked List · Hash Table · Linked List
Last reported Oct 2026
Design a stack data structure that supports standard push, pop, and top operations, along with a getMax operation that retrieves (but does not remove) the…
Companies: Confluent, Everpure, LinkedIn, Walmart Labs
Design · Doubly-Linked List · Linked List · Ordered Set
Last reported Oct 2026
Companies: Adobe, Amazon, Bloomberg, Microsoft
Depth-First Search · Doubly-Linked List · Linked List
Last reported Sep 2026
Implement a HashMap for integer keys/values without using built-in hash table libraries that supports put, get, and remove operations. The core challenge is to design…
Companies: Anduril, Canva, Chewy, Goldman Sachs +2
Array · Design · Hash Function · Hash Table
Last reported Sep 2026
Companies: Amazon, Meta, NVIDIA, Oracle +3
Divide and Conquer · Heap (Priority Queue) · Linked List · Merge Sort
Last reported Aug 2026
Companies: Amazon, Meta, Microsoft, NVIDIA
Hash Table · Linked List
Last reported Aug 2026
Companies: Apple, Bloomberg
Linked List
Last reported Jun 2026
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
Companies: eBay, Meta, Microsoft
Linked List · Recursion · Stack · Two Pointers
Last reported May 2026
Implement a BrowserHistory class that supports visiting URLs (which clears any forward history), moving back or forward up to a specified number of steps, and…
Companies: Amazon, Bloomberg, Chime
Array · Data Stream · Design · Doubly-Linked List
Last reported Apr 2026
Companies: Adobe, Google, LinkedIn, Meta +2
Linked List · Recursion
Last reported Feb 2026
Manage tokens that expire timeToLive seconds after creation/renewal, supporting generate, renew (only if the token is still unexpired), and countUnexpiredTokens (with…
Companies: Adobe, OpenAI
Design · Doubly-Linked List · Hash Table · Linked List
Last reported Feb 2026
Companies: Amazon, Bloomberg, Google, Meta +2
Linked List · Math · Recursion
Last reported Oct 2025
Companies: Meta, Pinterest
Linked List · Math · Stack
Last reported May 2025
Implement a fixed-size circular queue (ring buffer) supporting enqueue, dequeue, Front/Rear, isEmpty and isFull operations without using built-in queue types. The core…
Companies: NVIDIA
Array · Design · Linked List · Queue
Companies: Amazon, NVIDIA
Floyd's Cycle Finding Algorithm · Hash Table · Linked List · Two Pointers