Algorithm Design Patterns

A catalog of five moves, a search tree with most of its branches crossed out before they’re walked, and a guide for reading a new problem’s shape. This lesson is about picking the right move on the first try, not inventing one.

Before you start. You’ve already picked up five tools in this track - arrays, hash maps, trees, graphs, and the trick of a problem asking a smaller copy of itself from the last lesson. This lesson is not a sixth tool. It is how you choose between the five you already have, in the first thirty seconds of reading a new problem.