Submission #675707

#	Time	Username	Problem	Language	Result	Execution time	Memory
675707		Denkata	Bitaro’s Party (JOI18_bitaro)	C++14	100 / 100	1022 ms	220080 KiB

bitaro

#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
vector <int> v[200006];
int i,j,p,q,n,m,k,y,t;
int Q;
vector <pair <int,int>> best[200006];
const int crit = 150;
int used[200006];
int dp[200006];
int val[200006];
int marked[200006];
bool cmp(int x,int y)
{
    return val[x]>val[y];
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin>>n>>m>>Q;
    for(i=1; i<=m; i++)
    {
        cin>>p>>q;
        v[q].push_back(p);
    }
    for(i=1; i<=n; i++)
    {
        vector <int> all;
        for(auto j:v[i])
        {
            if(marked[j]!=i)
            {
                marked[j]=i;
                val[j]=1;
                all.push_back(j);
            }
            else val[j]=max(val[j],1);
            for(auto k:best[j])
            {
                if(marked[k.second]!=i)
                {
                    marked[k.second]=i;
                    all.push_back(k.second);
                    val[k.second]=k.first+1;
                }
                else val[k.second]=max(val[k.second],k.first+1);
            }
        }
        sort(all.begin(),all.end(),cmp);
        for(int j=0;j<min((int)all.size(),crit);j++)
            best[i].push_back({val[all[j]],all[j]});
    }
    while(Q--)
    {
        int party;
        cin>>party;
        cin>>y;
        for(i=1; i<=y; i++)
        {
            cin>>t;
            used[t]=Q+1;
        }

        bool fl=0;
        if(!best[party].empty())
        {
            for(i=0; i<(int)best[party].size(); i++)
            {
                //cout<<best[party][i].first<<" "<<best[party][i].second<<endl;
                if(used[best[party][i].second]!=Q+1)
                {
                  //  cout<<best[party][i].second<<" "<<best[party][i].first<<endl;
                    cout<<best[party][i].first<<endl;
                    fl=1;
                    break;
                }
            }
        }
        if(fl)continue;
        if(y<crit)
        {
            if(used[party]==Q+1)
                cout<<-1<<endl;
            else cout<<0<<endl;
            continue;
        }
        ///bruteforce
        fill(dp,dp+n+1,-1);
        for(i=1;i<=party;i++)
        {
            if(used[i]==Q+1)
                dp[i]=-1;
            else dp[i]=0;
            for(auto j:v[i])
            {
                if(dp[j]!=-1)
                    dp[i]=max(dp[i],dp[j]+1);
            }
        }
        cout<<dp[party]<<endl;
    }
    return 0;
}

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