Submission #58437

#	Time	Username	Problem	Language	Result	Execution time	Memory
58437		ksun48	Bitaro’s Party (JOI18_bitaro)	C++14	14 / 100	2085 ms	36836 KiB

bitaro

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

const int SIZE = 20;

int main(){
	cin.sync_with_stdio(0); cin.tie(0);
	int n, m, q;
	cin >> n >> m >> q;
	vector<int> edges[n];
	for(int i = 0; i < m; i++){
		int s, e;
		cin >> s >> e;
		s--; e--;
		edges[e].push_back(s);
	}
	vector<pair<int,int> > best[n];
	vector<int> seen(n, 0);
	for(int b = 0; b < n; b++){
		vector<pair<int,int> > cand;
		cand.push_back({0,b});
		for(int a : edges[b]){
			for(pair<int,int> x : best[a]){
				cand.push_back({x.first + 1, x.second});
			}
		}
		sort(cand.begin(), cand.end());
		reverse(cand.begin(), cand.end());
		for(pair<int,int> x : cand){
			if(seen[x.second]) continue;
			if(best[b].size() > SIZE) break;
			seen[x.second] = 1;
			best[b].push_back(x);
		}
		for(pair<int,int> x : cand){
			seen[x.second] = 0;
		}
	}
	vector<int> attend(n, 1);
	vector<int> dp(n, -1);
	for(int qq = 0; qq < q; qq++){
		int town, y;
		cin >> town >> y;
		town--;
		vector<int> bad(y);
		for(int i = 0; i < y; i++){
			cin >> bad[i];
			bad[i]--;
			attend[bad[i]] = 0;
		}
		if(y < SIZE){
			int ans = -1;
			for(pair<int,int> x : best[town]){
				if(attend[x.second]){
					ans = x.first;
					break;
				}
			}
			cout << ans << '\n';
		} else {
			for(int b = 0; b < n; b++){
				dp[b] = -1;
			}
			for(int b = 0; b < n; b++){
				if(attend[b]){
					dp[b] = 0;
				}
				for(int a : edges[b]){
					if(dp[a] >= 0){
						dp[b] = max(dp[b], dp[a] + 1);
					}
				}
			}
			cout << dp[town] << '\n';
		}
		for(int i = 0; i < y; i++){
			attend[bad[i]] = 1;
		}
	}
}

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