Submission #782715

#	Time	Username	Problem	Language	Result	Execution time	Memory
782715		Josia	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	1120 ms	155836 KiB

tickets

#include "tickets.h"
#include <vector>
#include <bits/stdc++.h>

using namespace std;

#define int long long

int find_maximum(signed k, std::vector<std::vector<signed>> x) {
	
	int colors = x.size();
	int ticketsPerColor = x[0].size();


	priority_queue<array<int, 4>> pq;	// val, col, indO, indN;

	int res = 0;

	for (int i=0; i<colors; i++) {
		for (int j = 0; j<k; j++) {
			res -= x[i][j];
			pq.push({x[i][j] + x[i][ticketsPerColor-(k-j)], i, j, ticketsPerColor-(k-j)});
		}
	}

	vector<pair<int, int>> numused(colors);

	for (int i = 0; i<colors; i++) numused[i].second = i;


	for (int i = 0; i<colors*k/2; i++) {
		res += pq.top()[0];
		numused[pq.top()[1]].first++;
		// used[pq.top()[1]][pq.top()[2]] = 0;
		// used[pq.top()[1]][pq.top()[3]] = 2;
		pq.pop();
	}



	set<pair<int, int>> blub;

	for (auto i: numused) blub.insert(i);

	vector<pair<int, int>> bounds(colors, {0, ticketsPerColor-1});

	vector<vector<signed>> ass(colors, vector<signed>(ticketsPerColor, -1));

	for (int i = 0; i<k; i++) {
		vector<pair<int, int>> round;
		for (int j = 0; j<colors/2; j++) {
			round.push_back(*blub.begin());
			blub.erase(blub.begin());

			ass[round.back().second][bounds[round.back().second].first] = i;
			bounds[round.back().second].first++;
		}
		for (int j = 0; j<colors/2; j++) {
			round.push_back(*blub.rbegin());
			blub.erase(*blub.rbegin());

			ass[round.back().second][bounds[round.back().second].second] = i;
			bounds[round.back().second].second--;

			round.back().first--;
		}

		for (auto i: round) blub.insert(i);
	}
	




	allocate_tickets(ass);


	return res;
}

• Subtask 1: 11 / 11
• Subtask 2: 16 / 16
• Subtask 3: 14 / 14
• Subtask 4: 14 / 14
• Subtask 5: 12 / 12
• Subtask 6: 23 / 23
• Subtask 7: 10 / 10