Submission #1258384

#	Time	Username	Problem	Language	Result	Execution time	Memory
1258384		ssitaram	Bitaro’s Party (JOI18_bitaro)	C++20	100 / 100	1590 ms	310044 KiB

bitaro

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

typedef long long ll;
typedef long double ld;

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n, m, q; cin >> n >> m >> q;
	int bl = 220;
	vector<vector<int>> to(n), into(n);
	for (int i = 0; i < m; ++i) {
		int a, b; cin >> a >> b;
		to[--a].push_back(--b);
		into[b].push_back(a);
	}
	vector<vector<pair<int, int>>> best(n);
	vector<int> from(n, -1);
	for (int i = 0; i < n; ++i) {
		from[i] = 0;
		vector<int> idxs = {i};
		for (int j : into[i]) {
			for (pair<int, int> k : best[j]) {
				if (from[k.second] == -1) {
					from[k.second] = k.first + 1;
					idxs.push_back(k.second);
				} else {
					from[k.second] = max(from[k.second], k.first + 1);
				}
			}
		}
		for (int j : idxs) {
			best[i].push_back({from[j], j});
		}
		sort(best[i].rbegin(), best[i].rend());
		while (best[i].size() > bl) best[i].pop_back();
		for (int j : idxs) {
			from[j] = -1;
		}
	}
	vector<bool> nouse(n);
	vector<int> mx(n);
	vector<int> c(n);
	while (q--) {
		int t, y; cin >> t >> y;
		for (int i = 0; i < y; ++i) {
			cin >> c[i];
			--c[i];
			nouse[c[i]] = true;
		}
		--t;
		if (y >= bl) {
			int ans = -1;
			for (int j = t; j >= 0; --j) {
				mx[j] = (j == t ? 0 : -1);
				for (int k : to[j]) {
					if (k <= t && mx[k] != -1) mx[j] = max(mx[j], mx[k] + 1);
				}
				if (!nouse[j]) ans = max(ans, mx[j]);
			}
			cout << ans << '\n';
		} else {
			auto it = best[t].begin();
			while (it != best[t].end() && nouse[it->second]) {
				++it;
			}
			if (it == best[t].end()) {
				cout << "-1\n";
			} else {
				cout << it->first << '\n';
			}
		}
		for (int i = 0; i < y; ++i) {
			nouse[c[i]] = false;
		}
	}
	return 0;
}

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