use std::collections::HashSet;
use std::iter::once;

    let mut workspace = Vec::new();
    let mut result = Vec::new();

    let mut dag = Vec::new();
    let mut descent = Vec::new();

        while workspace.len() <= worse {
            workspace.push(Vec::new());
            result.push(0);

        while dag.len() <= worse {
            dag.push(Vec::new());
            descent.push(HashSet::new());

        workspace[worse].push(better);

        dag[worse].push(better);

        (0..workspace.len()).rev().map(|x| (x, None)).collect();

        (0..dag.len()).rev().map(|x| (x, None)).collect();

        let d = std::mem::take(&mut workspace[i]);

        let d = std::mem::take(&mut dag[i]);

            result[s] = result[s].max(result[i] + 1);

            let e: HashSet<_> =
                once(i).chain(descent[i].iter().copied()).collect();
            descent[s].extend(e);

    result

    descent.into_iter().map(|d| d.len()).collect()