Function rs_graph::shortestpath::moorebellmanford::directed

pub fn directed<'a, G, W, F>(
    g: &'a G, 
    weights: F, 
    src: G::Node
) -> (NodeVec<&'a G, Option<G::Edge>>, Option<G::Node>) where
    G: 'a + IndexDigraph<'a>,
    W: NumAssign + Ord + Copy,
    F: Fn(G::Edge) -> W, 

The shortest-path algorithm by Moore-Bellman-Ford on a directed graph.

The function returns pair. The first element is the vector of the incoming edge for each (reachable) node. The second element a node on a negative cylce if it exists, otherwise it is None.

Example

use rs_graph::{LinkedListGraph, Buildable, Builder, EdgeVec, traits::*};
use rs_graph::shortestpath::moorebellmanford;

let mut weights = vec![];
let mut g = LinkedListGraph::<usize>::new_with(|b| {
    let nodes = b.add_nodes(7);
    for &(u,v,w) in [(0,1,-8), (1,4,-3), (2,0,2), (2,1,1), (2,5,-3), (3,1,0), (3,2,5),
                     (4,3,8), (5,3,-1), (6,3,4), (6,4,6), (6,5,3)].iter()
    {
        b.add_edge(nodes[u], nodes[v]);
        weights.push(w);
    }
});

let (pred, cycle) = moorebellmanford::directed(&g, |e| weights[g.edge_id(e)], g.id2node(6));
assert_eq!(cycle, None);
assert_eq!(pred[g.id2node(6)], None);
for &(u,p) in [(0,2), (1,0), (2,3), (4,1), (5,6)].iter() {
    assert_eq!(g.src(pred[g.id2node(u)].unwrap()), g.id2node(p));
}