// TOPIC

#hash-tables

4 articles

Hashing: The O(1) Superpower

How hash functions and buckets turn lookup into O(1) average time — the intuition behind collisions, chaining, and load factor that every engineer should own.

#hashing#hash-tables#fundamentals

11 min

◆◆IntermediateAmazonGoogle

LRU Cache

Implement an LRU cache with O(1) get and put: hash map plus doubly linked list, full Python code, eviction mechanics, and the interview traps.

#lru-cache#hash-tables#linked-lists

13 min

◆◆IntermediateGoogleAmazon

Hash Tables

The interview MVP. How hash functions turn arbitrary keys into O(1) lookups, what actually happens during a collision, and why "just use a hash map" is usually the right instinct.

#hash-tables#data-structures#hashing

10 min

◆◆IntermediateAmazonGoogle

The Sliding Window Pattern

Learn the sliding window technique: solve longest/shortest subarray and substring problems in O(n) with the expand-right, shrink-left template.

#sliding-window#two-pointers#arrays

11 min