functional graph utilities

[Astral-23]

#include "../Datastructure/dsu.hpp"

#include "../Datastructure/dsu.hpp"
struct functional_graph {
    int n;
    int d = 30;
    vec<int> sz, to, leader;
    vec<bool> on_cycle;
    vec<vec<int>> cycle, db;
    dsu uf;

    bool f = false;

    functional_graph(vec<int> &TO) : to(TO) {
        n = to.size();

        sz = leader = vec<int>(n);
        cycle.resize(n);
        on_cycle.resize(n, false);
        db.resize(d);
        uf = dsu(n);
        rep(i, 0, n) uf.merge(i, to[i]);

        vec<bool> seen(n, false);

        rep(i, 0, n) {
            int r = uf.leader(i);
            if(seen[r] == false) {
                seen[r] = true;
                sz[r] = uf.size(r);

                int v = r;
                rep(j, 0, uf.size(r)) v = to[v];
                int s = v;

                do {
                    cycle[r].push_back(v);
                    on_cycle[v] = true;
                    v = to[v];
                } while (v != s);
            }
        }
        rep(i, 0, n) leader[i] = uf.leader(i);
    }

    int jump(int p, ll k) {
        if(f == false) {
            f = true;
            db[0] = to;
            rep(t, 1, d) {
                rep(i, 0, n) {
                    db[t][i] = db[t-1][db[t-1][i]];
                }
            }
        }

        rep(i, 0, d) if(k >> i & 1) {
            p = db[i][p];
        }
        return p;
    }
};

jumpはverifyしてない　help! https://atcoder.jp/contests/abc357/submissions/54550056