Submission #1168825

#	Time	Username	Problem	Language	Result	Execution time	Memory
1168825		chikien2009	Bitaro’s Party (JOI18_bitaro)	C++20	100 / 100	1700 ms	411080 KiB

bitaro

#include <bits/stdc++.h>

using namespace std;

inline void setup()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int n, m, q, a, b, c, s[100000], d[100000];
int block_size;
vector<int> g[100000];
vector<pair<int, int>> f[100000];
bool banned[100000];

int main()
{
    setup();

    cin >> n >> m >> q;
    block_size = sqrt(n);
    while (m--)
    {
        cin >> a >> b;
        g[b - 1].push_back(a - 1);
    }
    fill_n(s, n, -1);
    for (int i = 0; i < n; ++i)
    {
        vector<pair<int, int>> v = {{0, i}}; 
        for (auto &j : g[i])
        {
            for (auto &k : f[j])
            {
                v.push_back({k.first + 1, k.second});
            }
        }
        sort(v.begin(), v.end(), greater<pair<int, int>>());
        for (int j = 0; j < v.size() && f[i].size() < block_size; ++j)
        {
            if (s[v[j].second] != i)
            {
                f[i].push_back(v[j]);  
                s[v[j].second] = i;
            }
        }
    }
    while (q--)
    {
        cin >> a >> b;
        a--;
        c = -1;
        for (int i = 0; i < b; ++i)
        {
            cin >> d[i];
            d[i] --;
            banned[d[i]] = true;
        }
        if (b < block_size)
        {
            for (auto & i : f[a])
            {
                if (!banned[i.second])
                {
                    c = i.first;
                    break;
                }
            }
        }
        else
        {
            fill_n(s, n, -1);
            s[a] = 0;
            for (int i = a; i >= 0; --i)
            {
                if (s[i] != -1)
                {
                    if (!banned[i])
                    {
                        c = max(c, s[i]);
                    }
                    for (auto & j : g[i])
                    {
                        s[j] = max(s[j], s[i] + 1);
                    }        
                }
            }
        }
        for (int i = 0; i < b; ++i)
        {
            banned[d[i]] = false;
        }
        cout << c << '\n';
    }
    return 0;
}

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