fn enumerate_shortest_paths()

in src/dachshund/algorithms/shortest_paths.rs [138:169]

• 29 lines of code
• 5 McCabe index (conditional complexity)

    fn enumerate_shortest_paths(
        &self,
        dist: &HashMap<NodeId, Option<usize>>,
        parents: &HashMap<NodeId, HashSet<NodeId>>,
        destination: NodeId,
    ) -> HashMap<NodeId, Vec<Vec<NodeId>>> {
        let mut nodes_by_distance: HashMap<usize, Vec<NodeId>> = HashMap::new();
        for (node_id, distance) in dist {
            if *node_id != destination {
                let d = distance.unwrap();
                nodes_by_distance.entry(d).or_insert_with(Vec::new);
                nodes_by_distance.get_mut(&d).unwrap().push(*node_id);
            }
        }
        nodes_by_distance.insert(0 as usize, vec![destination]);

        let mut distances: Vec<usize> = nodes_by_distance.keys().cloned().collect::<Vec<usize>>();
        distances.sort();

        // all the paths from a source to the destination;
        let mut paths: HashMap<NodeId, Vec<Vec<NodeId>>> = HashMap::new();
        paths.insert(destination, vec![vec![]]);
        for d in distances {
            let nodes: &Vec<NodeId> = nodes_by_distance.get(&d).unwrap();
            for node_id in nodes {
                let parent_ids = parents.get(node_id).unwrap();
                let new_paths = self.retrace_parent_paths(node_id, &parent_ids, &paths);
                paths.insert(*node_id, new_paths);
            }
        }
        paths
    }