A subgraph of G that is a tree and contains every vertex. Minimum spanning tree: weights sum minimised — Kruskal/Prim. Counted by Kirchhoff's matrix-tree theorem via det of the Laplacian.
A subgraph of G that is a tree and contains every vertex. Minimum spanning tree: weights sum minimised — Kruskal/Prim. Counted by Kirchhoff's matrix-tree theorem via det of the Laplacian.