hub

Graphs

Anything connected to anything.

Explore a network in rings, nearest first — using a queue.

Plunge down one path to the end, then back up and try the next.

Put jobs in an order where nothing happens before what it depends on.

The cheapest route through a weighted map — always finish the nearest place first.

Slower than Dijkstra, and it can do the one thing Dijkstra can't.

Dijkstra with a sense of direction — it guesses what's left, and aims.

Merge groups and ask 'are these two connected?' — in effectively constant time.