Method new

src/graph/directed/cycle.rs:71–78

(nv: usize)

impl DirectedCycle {
    fn new(nv: usize) -> Self {
        Self {
            cycle: None,
            edge_to: vec![0; nv],
            marked: vec![false; nv],
            on_stack: vec![false; nv],
        }
    }

    fn dfs(&mut self, graph: &dyn IGraph, v: usize) {
        self.on_stack[v] = true;