Submission #307938

#	Time	Username	Problem	Language	Result	Execution time	Memory
307938		jwvg0425	Carnival Tickets (IOI20_tickets)	C++17	11 / 100	2 ms	768 KiB

tickets

#include "tickets.h"
#include <vector>
#include <algorithm>
#include <set>
#define all(x) x.begin(), x.end()

using namespace std;
using i64 = long long int;

struct Ticket
{
	int color;
	int idx;
	int value;
};

i64 find_maximum(int k, vector<vector<int>> x)
{
	int n = x.size();
	int m = x[0].size();

	vector<Ticket> tickets;

	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < m; j++)
		{
			Ticket t;
			t.color = i;
			t.idx = j;
			t.value = x[i][j];
			tickets.push_back(t);
		}
	}

	sort(all(tickets), [](const Ticket& l, const Ticket& r)
	{
		return l.value < r.value;
	});

	i64 ret = 0;
	vector<vector<int>> ans(n, vector<int>(m, -1));
	vector<int> lrm(m, n / 2), rrm(m, n / 2);
	vector<set<int>> canUse(n);

	for (int i = 0; i < n; i++)
		for (int j = 0; j < m; j++)
			canUse[i].insert(j);

	int l = 0, r = n * m - 1;
	while (l < r)
	{
		ret += tickets[r].value - tickets[l].value;
		int lnxt = -1;
		for (auto& c : canUse[tickets[l].color])
		{
			if (lrm[c] == 0)
				continue;

			lnxt = c;
			break;
		}

		canUse[tickets[l].color].erase(lnxt);
		lrm[lnxt]--;
		ans[tickets[l].color][tickets[l].idx] = lnxt;

		int rnxt = -1;
		for (auto& c : canUse[tickets[r].color])
		{
			if (rrm[c] == 0)
				continue;

			rnxt = c;
			break;
		}

		canUse[tickets[r].color].erase(rnxt);
		rrm[rnxt]--;
		ans[tickets[r].color][tickets[r].idx] = rnxt;

		l++;
		r--;
	}

	allocate_tickets(ans);

	return ret;
}

• Subtask 1: 11 / 11
• Subtask 2: 0 / 16
• Subtask 3: 0 / 14
• Subtask 4: 0 / 14
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23
• Subtask 7: 0 / 10