Submission #983339

#	Time	Username	Problem	Language	Result	Execution time	Memory
983339		vjudge1	Sequence (APIO23_sequence)	C++17	28 / 100	2120 ms	1289960 KiB

sequence

#include "sequence.h"

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;

pair<int, int> mids(int sz) {
	int m1 = sz / 2;
	int m2 = sz / 2 + (sz % 2);
	return {m1, m2};
}

int sequence(int N, std::vector<int> A) {
	int res = 0;
	vector<map<int, int>> p(A.size() + 1);
	for (size_t i = 0; i < A.size(); ++i) {
		for (auto [key, val]: p[i]) {
			p[i + 1][key] = val;
		}
		p[i + 1][A[i]]++;
	}
	for (int l = 0; l < (int)A.size(); ++l) {
		tree<pair<int, int>, null_type, less<pair<int, int>>, rb_tree_tag, tree_order_statistics_node_update> st;
		for (int r = l; r < (int)A.size(); ++r) {
			st.insert(pair{A[r], r});
			auto [m1, m2] = mids(st.size() - 1);
			m1 = st.find_by_order(m1)->first;
			m2 = st.find_by_order(m2)->first;
			res = max(res, max(p[r + 1][m1] - p[l][m1], p[r + 1][m2] - p[l][m2]));
		}
	}
	return res;
}

• Subtask 1: 11 / 11
• Subtask 2: 17 / 17
• Subtask 3: 0 / 7
• Subtask 4: 0 / 12
• Subtask 5: 0 / 13
• Subtask 6: 0 / 22
• Subtask 7: 0 / 18