제출 #1318725

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1318725		khanhphucscratch	Bitaro’s Party (JOI18_bitaro)	C++20	100 / 100	697 ms	261020 KiB

bitaro

#include<bits/stdc++.h>
using namespace std;
const int bs = 320;
vector<int> ad[100005];
vector<pair<int, int>> option[100005];
bool used[100005];
void combine(vector<pair<int, int>> &a, vector<pair<int, int>> &b)
{
    vector<pair<int, int>> ans;
    int j = 0;
    for(int i = 0; i < a.size(); i++) if(ans.size() < bs){
        while(j < b.size() && b[j].first > a[i].first && ans.size() < bs){
            if(used[b[j].second] == 0){
                used[b[j].second] = 1;
                ans.push_back(b[j]);
            }
            j++;
        }
        if(ans.size() == bs) break;
        if(used[a[i].second] == 0){
            ans.push_back(a[i]); used[a[i].second] = 1;
        }
    }
    while(j < b.size() && ans.size() < bs){
        if(used[b[j].second] == 0){
            used[b[j].second] = 1;
            ans.push_back(b[j]);
        }
        j++;
    }
    a = ans;
    for(pair<int, int> &i : ans) used[i.second] = 0;
}
int dp[100005];
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n, m, q; cin>>n>>m>>q;
    for(int i = 1; i <= m; i++){
        int u, v; cin>>u>>v;
        ad[v].push_back(u);
    }
    //Now calculate sqrt(n) best option
    for(int i = 1; i <= n; i++){
        for(int v : ad[i]) combine(option[i], option[v]);
        if(option[i].size() < bs) option[i].push_back({-1, i});
        for(auto &j : option[i]) j.first++;
        //cerr<<"A"<<i<<endl;
        //for(auto j : option[i]) cerr<<j.first<<" "<<j.second<<endl;
    }
    for(int test = 0; test < q; test++){
        int u, nn; cin>>u>>nn;
        if(nn >= bs){
            //Brute solve
            memset(dp, 0, sizeof(dp));
            for(int i = 1; i <= nn; i++){
                int x; cin>>x; dp[x] = -1e9;
            }
            for(int i = 1; i <= u; i++) for(int v : ad[i]) dp[i] = max(dp[i], dp[v] + 1);
            cout<<max(dp[u], -1)<<'\n';
        }
        else{
            vector<int> a(nn);
            for(int i = 0; i < nn; i++) cin>>a[i];
            for(int i : a) used[i] = 1;
            int ans = -1;
            for(auto &i : option[u]) if(used[i.second] == 0){ans = i.first; break;}
            for(int i : a) used[i] = 0;
            cout<<ans<<'\n';
        }
    }
}

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