fn it_works()

in contests/__playground__/petgraph.rs [4:37]

• 24 lines of code
• 1 McCabe index (conditional complexity)

    fn it_works() {
        use petgraph::algo::{dijkstra, min_spanning_tree};
        use petgraph::data::FromElements;
        use petgraph::dot::{Config, Dot};
        use petgraph::graph::{NodeIndex, UnGraph};

        // Create an undirected graph with `i32` nodes and edges with `()` associated data.
        let g = UnGraph::<i32, ()>::from_edges(&[(1, 2), (2, 3), (3, 4), (1, 4)]);

        // Find the shortest path from `1` to `4` using `1` as the cost for every edge.
        let node_map = dijkstra(&g, 1.into(), Some(4.into()), |_| 1);
        assert_eq!(&1i32, node_map.get(&NodeIndex::new(4)).unwrap());

        // Get the minimum spanning tree of the graph as a new graph, and check that
        // one edge was trimmed.
        let mst = UnGraph::<_, _>::from_elements(min_spanning_tree(&g));
        assert_eq!(g.raw_edges().len() - 1, mst.raw_edges().len());

        // Output the tree to `graphviz` `DOT` format
        println!("{:?}", Dot::with_config(&mst, &[Config::EdgeNoLabel]));

        /*
           graph {
               0 [label="0"]
               1 [label="0"]
               2 [label="0"]
               3 [label="0"]
               4 [label="0"]
               1 -- 2
               3 -- 4
               2 -- 3
           }
        */
    }