Submission #410605

#	Time	Username	Problem	Language	Result	Execution time	Memory
410605		koioi.org-namnamseo	Bitaro’s Party (JOI18_bitaro)	C++17	0 / 100	12 ms	5412 KiB

bitaro

#include <iostream>
#include <vector>
#include <set>
#include <queue>
#include <utility>
#include <algorithm>
using namespace std;
using pp=pair<int, int>;
const int maxn = int(1e5) + 10;
const int B = 300;

int n, m, q;
vector<int> re[maxn];

vector<pp> prec[maxn];

int main()
{
	cin.tie(0)->sync_with_stdio(0);
	cin >> n >> m >> q;
	for (int i=1; i<=m; ++i) {
		int s, e; cin >> s >> e;
		re[e].push_back(s);
	}

	for (int i=1; i<=n; ++i) {
		priority_queue<pp> pq;
		pq.emplace(0, i);
		static int bi[maxn];
		for (int j:re[i]) {
			bi[j] = 0;
			pq.emplace(prec[j][0].first+1, j);
		}

		set<int> seen;
		for (int t=0; t<B && pq.size(); ++t) {
			auto [v, j] = pq.top(); pq.pop();
			if (j == i) {
				prec[i].emplace_back(0, i);
				continue;
			}
			int &ji = bi[j];
			if (seen.count(prec[j][ji].second)) {
				--t;
			} else {
				prec[i].emplace_back(v, prec[j][ji].second);
				seen.insert(prec[j][ji].second);
			}

			++ji;
			if (ji < int(prec[j].size())) {
				pq.emplace(prec[j][ji].first+1, j);
			}
		}
	}

	for (;q--;) {
		int dest, igs; cin >> dest >> igs;
		static int ign[maxn];
		for (int i=0; i<igs; ++i) cin >> ign[i];
		sort(ign, ign+igs); ign[igs] = 0;

		if (igs <= B) {
			bool found = 0;
			for (auto [dist, from]:prec[dest]) {
				if ((*lower_bound(ign, ign+igs, from)) != from) {
					cout << dist << '\n';
					found = 1;
					break;
				}
			}
			if (!found) {
				cout << "-1\n";
			}
			continue;
		}

		static queue<int> Q;
		Q.push(dest);
		static int qd[maxn];
		fill(qd+1, qd+dest+1, 0);
		int ans = -1;
		while (Q.size()) {
			int x = Q.front(); Q.pop();
			if ((*lower_bound(ign, ign+igs, x)) != x) {
				ans = qd[x];
			}
			for (int y:re[x]) if (!qd[y]) {
				qd[y] = qd[x] + 1;
				Q.push(y);
			}
		}

		cout << ans << '\n';
	}

	return 0;
}

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