
Big-O notation is how programmers describe how an algorithm's speed changes as the amount of data grows. This room covers the common complexity classes and what they mean for real programs, for anyone just starting to learn algorithms.

A tour of how hash tables give near-constant-time lookup, insertion and deletion, and the collisions and load factor that decide whether that promise holds. Written for anyone who has used a dictionary or map in code and wants to know what is happening underneath.