Method dfs

src/graph/directed/search.rs:37–44

(&mut self, graph: &dyn IGraph, v: usize)

impl DirectedDFS {
    fn dfs(&mut self, graph: &dyn IGraph, v: usize) {
        self.marked[v] = true;
        for &w in graph.adj(v) {
            if !self.marked[w] {
                self.dfs(graph, w);
            }
        }
    }
}