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MST definition; Kruskal's MST on 6-vertex graph

Short answer

A minimum spanning tree is a spanning tree with the smallest total edge weight. Kruskal's algorithm on this graph yields edges E-F(1), A-B(2), C-F(3), A-C(6), D-F(9), with minimum cost = 21.

What do you mean by minimum spanning tree? Find out the minimum spanning tree for given graph using Kruskal's algorithm. [Figure: undirected weighted graph on vertices A, B, C, D, E, F with edges A-B 2, A-C 6, A-F 7, B-D 11, C-F 3, C-E 5, D-F 9, E-F 1]

Minimum spanning tree

A spanning tree of a connected undirected graph G with V vertices is a subgraph that contains all V vertices, is connected and has no cycle (exactly V−1 edges). For a weighted graph, the spanning tree whose sum of edge weights is the smallest is the minimum spanning tree (MST). It is used in network design (least cable, pipeline or road cost).

Kruskal's algorithm on the given graph

6 vertices, so 5 edges are needed. Edges sorted: E-F 1, A-B 2, C-F 3, C-E 5, A-C 6, A-F 7, D-F 9, B-D 11.

StepEdgeWeightDecisionTotal
1E-F1accept1
2A-B2accept3
3C-F3accept6
4C-E5reject (cycle C-E-F)6
5A-C6accept12
6A-F7reject (cycle)12
7D-F9accept (5th edge)21

MST edges: E-F, A-B, C-F, A-C, D-F. Minimum cost = 21.

✓ Answer checked by Claude Opus 5.5 (high effort)

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