4 The following network shows the lengths, in miles, of roads connecting nine villages, \(A , B , \ldots , I\).
A programme of resurfacing some roads is undertaken to ensure that each village can access all other villages along a resurfaced road, while keeping the amount of road to be resurfaced to a minimum.
\includegraphics[max width=\textwidth, alt={}, center]{d666b2d9-cb14-4d29-a842-8c87f1b25dbd-08_1008_1043_589_497}
- Use Prim's algorithm starting from \(A\), showing the order in which you select the edges, to find a minimum spanning tree for the network.
- State the length of your minimum spanning tree.
- Draw your minimum spanning tree.
- Given that Prim's algorithm is used with different start vertices, state the final edge to be added to the minimum spanning tree if:
- the start vertex is \(E\);
- the start vertex is \(G\).
- Given that Kruskal's algorithm is used to find the minimum spanning tree, state which edge would be:
- the first to be included in the tree;
- the last to be included in the tree.