#hashing
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.
Hash Sets
A hash set is a hash table with the values ripped out — pure O(1) membership, dedup, and "have I seen this?" tracking. Master it and a whole class of O(n²) problems collapse to O(n).
Bloom Filters
A probabilistic set that answers "definitely not" or "maybe yes" using a bit array and k hash functions — orders of magnitude smaller than a hash set, with a tunable false-positive rate and mathematically guaranteed zero false negatives.
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.