Submission #693187

#	Time	Username	Problem	Language	Result	Execution time	Memory
693187		four_specks	Bitaro’s Party (JOI18_bitaro)	C++17	0 / 100	4 ms	1356 KiB

bitaro

#include <bits/stdc++.h>

using namespace std;

namespace
{
} // namespace

void solve()
{
    const int SQ = 20;

    int n, m, q;
    cin >> n >> m >> q;

    vector<vector<int>> adj(n), adj_rev(n);
    for (int i = 0; i < m; i++)
    {
        int u, v;
        cin >> u >> v, --u, --v;

        adj[v].push_back(u);
    }

    vector<vector<pair<int, int>>> take(n);
    for (int i = 0; i < n; i++)
    {
        take[i].emplace_back(0, i);
        for (int j : adj[i])
        {
            for (auto [l, k] : take[j])
                take[i].emplace_back(l + 1, k);
        }
        sort(take[i].begin(), take[i].end());
        take[i].erase(unique(take[i].begin(), take[i].end()), take[i].end());
        if ((int)take[i].size() > SQ)
            take[i].erase(take[i].begin() + SQ, take[i].end());
    }

    vector<bool> bad(n);
    for (int c = 0; c < q; c++)
    {
        int u, y;
        cin >> u >> y, --u;

        vector<int> busy(y);
        for (int &v : busy)
            cin >> v, --v;

        for (int v : busy)
            bad[v] = 1;

        if (y >= SQ)
        {
            vector<int> dp(u + 1);
            for (int v : busy)
                dp[v] = -1;
            for (int i = 0; i <= u; i++)
            {
                for (int j : adj[i])
                {
                    if (dp[j] != -1)
                        dp[i] = max(dp[i], dp[j] + 1);
                }
            }

            cout << dp[u] << '\n';
        }
        else
        {
            int res = -1;
            for (auto [l, v] : take[u])
            {
                if (!bad[v])
                    res = max(res, l);
            }

            cout << res << '\n';
        }

        for (int v : busy)
            bad[v] = 0;
    }
}

int main()
{
    ios_base::sync_with_stdio(false), cin.tie(NULL);

    solve();

    return 0;
}

• Subtask 1: 0 / 7
• Subtask 2: 0 / 7
• Subtask 3: 0 / 86