Method bfs

src/graph/util/paths.rs:126–141

(&mut self, g: &dyn IGraph, s: usize)

    }

    fn bfs(&mut self, g: &dyn IGraph, s: usize) {
        let mut queue = Queue::default();
        self.marked[s] = true;
        self.dist_to[s] = 0;
        queue.enqueue(s);
        while let Some(v) = queue.dequeue() {
            for &w in g.adj(v) {
                if !self.marked[w] {
                    self.edge_to[w] = v;
                    self.dist_to[w] = self.dist_to[v] + 1;
                    self.marked[w] = true;
                    queue.enqueue(w);
                }
            }
        }
    }
}