ABC 372

D - Buildings

解説 AC.

void solve() {
    ll n;
    cin >> n;
    vll h(n);
    rep(i, n) cin >> h[i];

    vll ans(n);
    vll st;
    for (int i = n - 1; i >= 0; i--) {
        ans[i] = st.size();
        while (st.size() != 0 && st.back() < h[i]) {
            st.pop_back();
        }
        st.push_back(h[i]);
    }
    print(ans);
}

E - K-th Largest Connected Components

https://atcoder.jp/contests/abc372/tasks/abc372_e

解説 AC

void solve() {
    ll N, Q;
    cin >> N >> Q;

    dsu uf(N);
    vvint nodes(N);
    rep(i, N) {
        nodes[i].push_back(i);
    }

    rep(i, Q) {
        int q, a, b;
        cin >> q >> a >> b;
        if (q == 1) {
            int u = a - 1, v = b - 1;
            if (uf.same(u, v))
                continue;
            int ou = uf.leader(u);
            int ov = uf.leader(v);
            int newl = uf.merge(u, v);
            vint tmp = nodes[ou];
            for (auto x : nodes[ov])
                tmp.push_back(x);
            sort(rall(tmp));
            vint newv;
            for (int i = 0; i < 10 && i < tmp.size(); i++) {
                newv.push_back(tmp[i]);
            }
            nodes[newl] = newv;
        } else {
            int v = a - 1, k = b;
            int l = uf.leader(v);
            if (nodes[l].size() >= k) {
                cout << nodes[l][k - 1] + 1 << endl;
            } else {
                cout << -1 << endl;
            }
        }
    }
}