Graphs (BFS, DFS, Dijkstra, topological sort)

Dots and the lines between them, the shape this whole lesson is built on. The same picture backs routing in Networking (How a parcel finds any house on earth), the graph data model in Data Models and Query Languages, and the dataflow DAGs in Batch Processing.

Before you start. You need only arrays: a numbered list where you can jump straight to slot i. Nothing about graphs is assumed here - every new word below is shown doing something before it gets named.