Connected Components
Run BFS or DFS from every unvisited vertex; each run colours one component.
Decision · step 2 of 13BFS and DFS: Three components
Vertex 0 has no component number yet, so it starts component 1. Traverse from it.
What you will see
Each traversal floods one island with a component number.
Cost
| Best | O(V + E) |
|---|---|
| Average | O(V + E) |
| Worst | O(V + E) |
| Space | O(V) |
How you work with it here
play it through, step one change at a time, scrub to any step, run it on your own input, predict what happens next, try operations in any order.
Screen readers: Vertices announce name, neighbours and state (in queue, visited, current); each step announces which vertex is processed and which neighbours are discovered.
Reduced motion: Frontier and visited changes are crossfades; the traversal edge is emphasized without a travelling token.
Before this
Taught by the same lesson
BFS and DFS covers these too, in the same run.