Grokking Algorithms: An illustrated guide for programmers and other curious people

by Aditya Y. Bhargava

Big O notation is special notation that tells you how fast an algorithm is.

When you write a recursive function, you have to tell it when to stop recursing. That’s why every recursive function has two parts: the base case, and the recursive case.

Hash tables are a powerful data structure because they’re so fast and they let you model data in a different way.