Submission #1107112

#	Time	Username	Problem	Language	Result	Execution time	Memory
1107112		xnqs	Triple Jump (JOI19_jumps)	C++17	0 / 100	79 ms	2420 KiB

jumps

// TODO implement optimally

#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <utility>
#include <algorithm>
#include <cmath>

int x, q;
int arr[500005];

int range_max_query(int l, int r) {
	int ret = 0;
	for (int i = l; i <= r; i++) {
		ret = std::max(ret,arr[i]);
	}
	return ret;
}

struct PQComp {
	bool operator() (int a, int b) {
		return arr[a] < arr[b];
	}
};

// take the 2 maxes, let their positions be 1 and 2
// therefore we have the following cases
//
// 1: ---1##--2
// 2: --###1--2
// 3: -1-2-####
int query(int l, int r) {
	if (r-l+1<=20) {
		int ret = 0;
		for (int i = l; i <= r; i++) {
			for (int j = i+1; j <= r; j++) {
				for (int k = j+(j-i); k <= r; k++) {
					ret = std::max(ret, arr[i]+arr[j]+arr[k]);
				}
			}
		}
		return ret;
	}

	std::priority_queue<int, std::vector<int>, PQComp> pq;
	for (int i = l; i <= r; i++) {
		pq.emplace(i);
	}

	std::vector<int> pos;
	while (!pq.empty()&&pos.size()<20) {
		int k = pq.top();
		pq.pop();
		pos.emplace_back(k);
	}

	int ret = 0;
	for (auto m1 : pos) {
		for (auto m2 : pos) {
			if (m1==m2) {
				continue;
			}

			if (m1>m2) std::swap(m1,m2);

			// 1
			for (int i = m1+1; std::abs(m1-i) <= std::abs(m2-i) && i <= r; i++) {
				//std::cout << m1 << " " << i << " " << m2 << " " << arr[m1]+arr[m2]+arr[i] << "\n";
				if (ret<arr[m1]+arr[m2]+arr[i]) {
					ret = arr[m1]+arr[m2]+arr[i];
				}
			}
			// 2
			for (int i = m1-1; std::abs(m1-i) <= std::abs(m1-m2) && i >= l; i--) {
				//std::cout << i << " " << m1 << " " << m2 << " " << arr[m1]+arr[m2]+arr[i] << "\n";
				if (ret<arr[m1]+arr[m2]+arr[i]) {
					ret = arr[m1]+arr[m2]+arr[i];
				}
			}
			// 3
			for (int i = m2+(m2-m1); i <= r; i++) {
				//std::cout << m1 << " " << m2 << " " << i << " " << arr[m1]+arr[m2]+arr[i] << "\n";
				if (ret<arr[m1]+arr[m2]+arr[i]) {
					ret = arr[m1]+arr[m2]+arr[i];
				}
			}
		}
	}

	return ret;
}

int main() {
	std::ios_base::sync_with_stdio(false);
	std::cin.tie(NULL);
	std::cout.tie(NULL);

	std::cin >> x;
	for (int i = 1; i <= x; i++) {
		std::cin >> arr[i];
	}

	std::cin >> q;
	while (q--) {
		int l, r;
		std::cin >> l >> r;
		std::cout << query(l,r) << "\n";
	}
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 14
• Subtask 3: 0 / 27
• Subtask 4: 0 / 54