Submission #526829

#	Time	Username	Problem	Language	Result	Execution time	Memory
526829		fhvirus	Two Antennas (JOI19_antennas)	C++17	100 / 100	597 ms	38724 KiB

antennas

#include<bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast")

const int INF = 1e9 + 7;

struct SGT {
	int n; vector<int> min_height, tag, max_dif;
	SGT(int _n): n(_n), min_height(n * 4 + 4, INF),
		tag(n * 4 + 4, -INF), max_dif(n * 4 + 4, -1) {}
	void upd(int i, int v) {
		tag[i] = max(tag[i], v);
		max_dif[i] = max(max_dif[i], tag[i] - min_height[i]);
	}
	void push(int i) {
		if (tag[i] == -INF) return;
		upd(i * 2, tag[i]);
		upd(i * 2 + 1, tag[i]);
		tag[i] = -INF;
	}
	void pull(int i) {
		min_height[i] = min(min_height[i * 2], min_height[i * 2 + 1]);
		max_dif[i] = max(max_dif[i * 2], max_dif[i * 2 + 1]);
	}
	void set_height(int i, int l, int r, int p, int v) {
		if (l == r) {
			min_height[i] = v;
			tag[i] = -INF;
			return;
		}
		push(i);
		int m = (l + r) / 2;
		if (p <= m) set_height(i * 2, l, m, p, v);
		else set_height(i * 2 + 1, m + 1, r, p, v);
		pull(i);
		return;
	}
	void chmax(int i, int l, int r, int ql, int qr, int v) {
		if (ql <= l and r <= qr) {
			upd(i, v);
			return;
		}
		push(i);
		int m = (l + r) / 2;
		if (ql <= m) chmax(i * 2, l, m, ql, qr, v);
		if (m < qr) chmax(i * 2 + 1, m + 1, r, ql, qr, v);
		pull(i);
		return;
	}
	int query(int i, int l, int r, int ql, int qr) {
		if (ql <= l and r <= qr)
			return max_dif[i];
		push(i);
		int m = (l + r) / 2, ans = -1;
		if (ql <= m) ans = max(ans, query(i * 2, l, m, ql, qr));
		if (m < qr) ans = max(ans, query(i * 2 + 1, m + 1, r, ql, qr));
		return ans;
	}
	void set_height(int p, int v) { set_height(1, 1, n, p, v); }
	void chmax(int ql, int qr, int v) { chmax(1, 1, n, ql, qr, v); }
	int query(int ql, int qr) { return query(1, 1, n, ql, qr); }
};

signed main() {
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

	int N; cin >> N;
	vector<int> H(N + 1), A(N + 1), B(N + 1);
	for (int i = 1; i <= N; ++i)
		cin >> H[i] >> A[i] >> B[i];

	int Q; cin >> Q;
	vector<int> L(Q + 1), R(Q + 1);
	for (int i = 1; i <= Q; ++i)
		cin >> L[i] >> R[i];

	vector<int> ans(Q + 1, -1);
	auto solve = [&]() -> void {
		vector<vector<int>> in(N + 1);
		vector<vector<int>> ou(N + 2);
		for (int i = 1; i <= N; ++i) {
			int lb = min(N + 1, i + A[i]);
			int rb = min(N, i + B[i]);
			if (lb < N + 1) {
				in[lb].push_back(i);
				ou[rb + 1].push_back(i);
			}
		}

		vector<vector<pair<int, int>>> qs(N + 1);
		for (int i = 1; i <= Q; ++i)
			qs[R[i]].emplace_back(L[i], i);

		SGT sgt(N);
		for (int i = 1; i <= N; ++i) {
			for (int &j: in[i])
				sgt.set_height(j, H[j]);
			for (int &j: ou[i])
				sgt.set_height(j, INF);

			int lb = max(1, i - B[i]);
			int rb = max(0, i - A[i]);
			if (rb > 0)
				sgt.chmax(lb, rb, H[i]);

			for (auto &[ql, id]: qs[i])
				ans[id] = max(ans[id], sgt.query(ql, i));
		}
	};

	solve();
	reverse(begin(H) + 1, end(H));
	reverse(begin(A) + 1, end(A));
	reverse(begin(B) + 1, end(B));
	for (int i = 1; i <= Q; ++i) {
		L[i] = N - L[i] + 1;
		R[i] = N - R[i] + 1;
		swap(L[i], R[i]);
	}
	solve();

	for (int i = 1; i <= Q; ++i)
		cout << ans[i] << '\n';

	return 0;
}

• Subtask 1: 2 / 2
• Subtask 2: 11 / 11
• Subtask 3: 22 / 22
• Subtask 4: 65 / 65