Submission #1004692

#	Time	Username	Problem	Language	Result	Execution time	Memory
1004692		phoenix	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	594 ms	116476 KiB

tickets

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

using namespace std;
using ll = long long;

long long find_maximum(int k, vector<vector<int>> x) {
	int n = x.size(), m = x[0].size();
	long long S = 0;
	vector<vector<int>> answer(n, vector<int>(m, -1));
	vector<int> l(n, -1), r(n, m);

	priority_queue<pair<ll, int>> pq;

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < k; j++) {
			S -= x[i][++l[i]];
			pq.push({x[i][j] + x[i][m - k + j], i});
		}
	}

	for (int iter = 0; iter < (n / 2) * k; iter++) {
		int i = pq.top().second;
		pq.pop();
		S += x[i][--r[i]];
		S += x[i][l[i]--];
	}

	for (int iter = 0; iter < k; iter++) {
		int cnt = 0;
		for (int i = 0; i < n; i++) {
			if (r[i] == m) {
				answer[i][l[i]--] = iter;
				cnt++;
			}
		}
		assert(cnt <= n / 2);
		for (int i = 0; i < n; i++) {
			if (r[i] == m) continue;
			if (cnt < n / 2 && l[i] >= 0) {
				answer[i][l[i]--] = iter;
				cnt++;
			} else {
				answer[i][r[i]++] = iter;
			}
		}
	}

	allocate_tickets(answer);
	return S;
}

• 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