Submission #471587

#	Time	Username	Problem	Language	Result	Execution time	Memory
471587		Rainbowbunny	Bitaro’s Party (JOI18_bitaro)	C++17	100 / 100	1587 ms	414148 KiB

bitaro

#include <bits/stdc++.h>
using namespace std;

const int MAXN = 100005;
const int SQRT = 300;

int n, m, q, c;
int dp[MAXN], a[MAXN];
bool Mark[MAXN];
vector <int> Adj[MAXN];
vector <pair <int, int> > Dist[MAXN];

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> n >> m >> q;
    for(int i = 1; i <= m; i++)
    {
        int u, v;
        cin >> u >> v;
        Adj[v].push_back(u);
    }
    for(int i = 1; i <= n; i++)
    {
        Dist[i].emplace_back(0, i);
        for(auto x : Adj[i])
        {
            c = 0;
            vector <pair <int, int> > tmp;
            int pt0 = 0, pt1 = 0;
            while(pt0 < (int)Dist[i].size() and pt1 < (int)Dist[x].size() and tmp.size() < SQRT)
            {
                if(Dist[i][pt0].first > Dist[x][pt1].first + 1)
                {  
                    if(!Mark[Dist[i][pt0].second])
                    {
                        Mark[Dist[i][pt0].second] = 1;
                        a[c] = Dist[i][pt0].second;
                        c++;
                        tmp.emplace_back(Dist[i][pt0]);
                    }
                    pt0++;
                }
                else
                {
                    if(!Mark[Dist[x][pt1].second])
                    {
                        Mark[Dist[x][pt1].second] = 1;
                        a[c] = Dist[x][pt1].second;
                        c++;
                        tmp.emplace_back(Dist[x][pt1].first + 1, Dist[x][pt1].second);
                    }
                    pt1++;
                }
            }
            while(pt0 < (int)Dist[i].size() and tmp.size() < SQRT)
            {
                if(!Mark[Dist[i][pt0].second])
                {
                    Mark[Dist[i][pt0].second] = 1;
                    a[c] = Dist[i][pt0].second;
                    c++;
                    tmp.emplace_back(Dist[i][pt0]);
                }
                pt0++;
            }
            while(pt1 < (int)Dist[x].size() and tmp.size() < SQRT)
            {
                if(!Mark[Dist[x][pt1].second])
                {
                    Mark[Dist[x][pt1].second] = 1;
                    a[c] = Dist[x][pt1].second;
                    c++;
                    tmp.emplace_back(Dist[x][pt1].first + 1, Dist[x][pt1].second);
                }
                pt1++;
            }
            swap(tmp, Dist[i]);
            for(int j = 0; j < c; j++)
            {
                Mark[a[j]] = false;
            }
        }
    }
    while(q--)
    {
        int t, sz;
        cin >> t >> sz;
        vector <int> tmp(sz);
        for(auto &x : tmp)
        {
            cin >> x;
            Mark[x] = true;
        }
        bool ok = false;
        for(int i = 0; i < (int)Dist[t].size(); i++)
        {
            if(!Mark[Dist[t][i].second])
            {
                ok = true;
                cout << Dist[t][i].first << '\n';
                break;
            }
        }
        if(!ok)
        {
            int ans = -1;
            for(int i = 1; i <= n; i++)
            {
                dp[i] = -1e9;
            }
            dp[t] = 0;
            for(int i = t; i >= 1; i--)
            {
                for(auto x : Adj[i])
                {
                    dp[x] = max(dp[x], dp[i] + 1);
                }
                if(!Mark[i])
                {
                    ans = max(ans, dp[i]);
                }
            }
            cout << ans << '\n';
        }
        for(auto x : tmp)
        {
            Mark[x] = false;
        }
    }
}

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