1582 articles
Design a simplified Twitter with follow/unfollow and a news feed that returns the 10 most recent tweets across followed users — combining hash maps, social graph storage, and k-way heap merging.
Find all index pairs (i, j) such that words[i] + words[j] forms a palindrome, using a reverse-word hashmap and systematic prefix/suffix palindrome splits in O(N * K^2) time. A FAANG hard problem that fuses string algorithms with hash table mastery.
Complete cheatsheet for Hashing & Maps: all 7 patterns, Big O reference, template code, and MAANG priority guide.
Master heaps and priority queues for FAANG interviews: 7 core patterns including Top K, Two Heaps, Merge K, scheduling, and streaming median problems.
Solve LeetCode 703 Kth Largest Element in a Stream — a classic Amazon and Meta phone-screen heap problem using a fixed-size min-heap of size K.