Method add_edge

src/graph/shortest/ew_digraph.rs:23–28

(&mut self, v: usize, w: usize, weight: f32)

    }

    fn add_edge(&mut self, v: usize, w: usize, weight: f32) {
        let e = DirectedEdge::new(v, w, weight);
        self.adj[v].push_front(e);
        self.in_degree[w] += 1;
        self.ne += 1;
    }

    fn adj(&self, v: usize) -> Iter<'_, DirectedEdge> {
        self.adj[v].iter()