Submission #456182

#	Time	Username	Problem	Language	Result	Execution time	Memory
456182		arminatarod	Triple Jump (JOI19_jumps)	C++17	100 / 100	1587 ms	87896 KiB

jumps

#include <bits/stdc++.h>

using namespace std;

constexpr int MAXN = 500005;

constexpr int MAXINT = 1073741823;

vector<int> pairs[MAXN];

vector<pair<int, int>> queries[MAXN];

stack<int> s;

int a[MAXN], answer[MAXN];

struct node {
	int result = 0, maximum_pair = 0, maximum_a = 0;
} segment[MAXN * 4];

node merge(node x, node y) {
	node result;
	result.maximum_a = max(x.maximum_a, y.maximum_a);
	result.maximum_pair = max(x.maximum_pair, y.maximum_pair);
	result.result = max(x.maximum_pair + y.maximum_a, max(x.result, y.result));
	return result;
}

node get_answer(int from, int to, int current, int beginning, int ending) {
	node nothing;
	if (from > ending || to < beginning)
		return nothing;
	else if (beginning <= from && to <= ending)
		return segment[current];
	int mid = (from + to) / 2;
	return merge(get_answer(from, mid, current * 2 + 1, beginning, ending), get_answer(mid + 1, to, current * 2 + 2, beginning, ending));
}

void update(int from, int to, int current, int index, int value, bool is_pair) {
	if (from > index || to < index)
		return;
	else if (from == to) {
		if (is_pair)
			segment[current].maximum_pair = max(segment[current].maximum_pair, value);
		else
			segment[current].maximum_a = max(segment[current].maximum_a, value);
		segment[current].result = max(segment[current].result, segment[current].maximum_a + segment[current].maximum_pair);
		return;
	}
	int mid = (from + to) / 2;
	update(from, mid, current * 2 + 1, index, value, is_pair);
	update(mid + 1, to, current * 2 + 2, index, value, is_pair);
	segment[current] = merge(segment[current * 2 + 1], segment[current * 2 + 2]);
	return;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n, t, from, to;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> a[i];
		update(0, n - 1, 0, i, a[i], false);
		while (!s.empty() && a[s.top()] <= a[i]) {
			pairs[s.top()].push_back(i);
			s.pop();
		}
		if (!s.empty())
			pairs[s.top()].push_back(i);
		s.push(i);
	}
	cin >> t;
	for (int q = 0; q < t; q++) {
		cin >> from >> to;
		from--;
		to--;
		queries[from].emplace_back(to, q);
	}
	for (int i = n - 1; i >= 0; i--) {
		for (int j : pairs[i])
			if (2 * j - i < n)
				update(0, n - 1, 0, 2 * j - i, a[i] + a[j], true);
		for (pair<int, int> j : queries[i])
			answer[j.second] = get_answer(0, n - 1, 0, i + 2, j.first).result;
	}
	for (int q = 0; q < t; q++)
		cout << answer[q] << '\n';
	return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 14 / 14
• Subtask 3: 27 / 27
• Subtask 4: 54 / 54