Submission #670289

#	Time	Username	Problem	Language	Result	Execution time	Memory
670289		SanguineChameleon	Two Antennas (JOI19_antennas)	C++17	100 / 100	600 ms	50916 KiB

antennas

// BEGIN BOILERPLATE CODE

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

#ifdef KAMIRULEZ
	const bool kami_loc = true;
	const long long kami_seed = 69420;
#else
	const bool kami_loc = false;
	const long long kami_seed = chrono::steady_clock::now().time_since_epoch().count();
#endif

const string kami_fi = "kamirulez.inp";
const string kami_fo = "kamirulez.out";
mt19937_64 kami_gen(kami_seed);

long long rand_range(long long rmin, long long rmax) {
	uniform_int_distribution<long long> rdist(rmin, rmax);
	return rdist(kami_gen);
}

long double rand_real(long double rmin, long double rmax) {
	uniform_real_distribution<long double> rdist(rmin, rmax);
	return rdist(kami_gen);
}

void file_io(string fi, string fo) {
	if (fi != "" && (!kami_loc || fi == kami_fi)) {
		freopen(fi.c_str(), "r", stdin);
	}
	if (fo != "" && (!kami_loc || fo == kami_fo)) {
		freopen(fo.c_str(), "w", stdout);
	}
}

void set_up() {
	if (kami_loc) {
		file_io(kami_fi, kami_fo);
	}
	ios_base::sync_with_stdio(0);
	cin.tie(0);
}

void just_do_it();

void just_exec_it() {
	if (kami_loc) {
		auto pstart = chrono::steady_clock::now();
		just_do_it();
		auto pend = chrono::steady_clock::now();
		long long ptime = chrono::duration_cast<chrono::milliseconds>(pend - pstart).count();
		string bar(50, '=');
		cout << '\n' << bar << '\n';
		cout << "Time: " << ptime << " ms" << '\n';
	}
	else {
		just_do_it();
	}
}

int main() {
	set_up();
	just_exec_it();
	return 0;
}

// END BOILERPLATE CODE

// BEGIN MAIN CODE

const int ms = 2e5 + 20;
const int inf = 1e9 + 20;
int h[ms];
int a[ms];
int b[ms];
int res[ms];
int n, q;

struct query {
	int id, lt, rt;
};

struct node {
	int ma, mb, ts;
};

query qs[ms];
node tr[ms * 4];
vector<int> add[ms];
vector<int> rem[ms];
vector<query> qr[ms];

void push(int cc) {
	tr[cc * 2].mb = max(tr[cc * 2].mb, tr[cc].mb);
	tr[cc * 2].ts = max(tr[cc * 2].ts, tr[cc * 2].mb - tr[cc * 2].ma);
	tr[cc * 2 + 1].mb = max(tr[cc * 2 + 1].mb, tr[cc].mb);
	tr[cc * 2 + 1].ts = max(tr[cc * 2 + 1].ts, tr[cc * 2 + 1].mb - tr[cc * 2 + 1].ma);
	tr[cc].mb = -inf;
}

void update_a(int cc, int lt, int rt, int px, int pp) {
	if (lt == rt) {
		tr[cc].ma = pp;
		tr[cc].mb = -inf;
		return;
	}
	push(cc);
	int mt = (lt + rt) / 2;
	if (px <= mt) {
		update_a(cc * 2, lt, mt, px, pp);
	}
	else {
		update_a(cc * 2 + 1, mt + 1, rt, px, pp);
	}
	tr[cc].ma = min(tr[cc * 2].ma, tr[cc * 2 + 1].ma);
	tr[cc].ts = max(tr[cc * 2].ts, tr[cc * 2 + 1].ts);
}

void update_b(int cc, int lt, int rt, int ql, int qr, int pp) {
	if (lt == ql && rt == qr) {
		tr[cc].mb = max(tr[cc].mb, pp);
		tr[cc].ts = max(tr[cc].ts, tr[cc].mb - tr[cc].ma);
		return;
	}
	push(cc);
	int mt = (lt + rt) / 2;
	if (qr <= mt) {
		update_b(cc * 2, lt, mt, ql, qr, pp);
	}
	else if (ql >= mt + 1) {
		update_b(cc * 2 + 1, mt + 1, rt, ql, qr, pp);
	}
	else {
		update_b(cc * 2, lt, mt, ql, mt, pp);
		update_b(cc * 2 + 1, mt + 1, rt, mt + 1, qr, pp);
	}
	tr[cc].ts = max(tr[cc * 2].ts, tr[cc * 2 + 1].ts);
}

int get(int cc, int lt, int rt, int ql, int qr) {
	if (lt == ql && rt == qr) {
		return tr[cc].ts;
	}
	push(cc);
	int mt = (lt + rt) / 2;
	if (qr <= mt) {
		return get(cc * 2, lt, mt, ql, qr);
	}
	else if (ql >= mt + 1) {
		return get(cc * 2 + 1, mt + 1, rt, ql, qr);
	}
	else {
		return max(get(cc * 2, lt, mt, ql, mt), get(cc * 2 + 1, mt + 1, rt, mt + 1, qr));
	}
}

void solve() {
	fill_n(tr, ms * 4, node({inf, -inf, -inf}));
	for (int i = 1; i <= n; i++) {
		add[i].clear();
		rem[i].clear();
		qr[i].clear();
	}
	for (int i = 1; i <= n; i++) {
		int lt = i + a[i];
		int rt = i + b[i];
		if (lt <= n) {
			add[lt].push_back(i);
			rem[min(rt, n)].push_back(i);
		}
	}
	for (int i = 1; i <= q; i++) {
		qr[qs[i].rt].push_back(qs[i]);
	}
	for (int i = 1; i <= n; i++) {
		for (auto x: add[i]) {
			update_a(1, 1, n, x, h[x]);
		}
		int lt = i - b[i];
		int rt = i - a[i];
		if (rt >= 1) {
			update_b(1, 1, n, max(lt, 1), rt, h[i]);
		}
		for (auto x: qr[i]) {
			res[x.id] = max(res[x.id], get(1, 1, n, x.lt, x.rt));
		}
		for (auto x: rem[i]) {
			update_a(1, 1, n, x, inf);
		}
	}
}

void just_do_it() {
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> h[i] >> a[i] >> b[i];
	}
	cin >> q;
	for (int i = 1; i <= q; i++) {
		cin >> qs[i].lt >> qs[i].rt;
		qs[i].id = i;
		res[i] = -inf;
	}
	solve();
	reverse(h + 1, h + n + 1);
	reverse(a + 1, a + n + 1);
	reverse(b + 1, b + n + 1);
	for (int i = 1; i <= q; i++) {
		qs[i].lt = n + 1 - qs[i].lt;
		qs[i].rt = n + 1 - qs[i].rt;
		swap(qs[i].lt, qs[i].rt);
	}
	solve();
	for (int i = 1; i <= q; i++) {
		cout << max(res[i], -1) << '\n';
	}
}

// END MAIN CODE

Compilation message (stderr)

antennas.cpp: In function 'void file_io(std::string, std::string)':
antennas.cpp:30:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |   freopen(fi.c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
antennas.cpp:33:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |   freopen(fo.c_str(), "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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