Submission #302196

#	Time	Username	Problem	Language	Result	Execution time	Memory
302196		kriii	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	1220 ms	62360 KiB

tickets

#include "tickets.h"
#include <algorithm>
#include <vector>
using namespace std;

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

	long long ans = 0;
	vector<pair<int, int> > sum;
	for (int i = 0; i < n; i++){
		for (int j = 0; j < k; j++){
			ans -= x[i][j];
			sum.push_back({ x[i][j] + x[i][m - k + j], i });
		}
	}

	sort(sum.rbegin(), sum.rend());

	int neg[1500] = { 0, }, pos[1500] = { 0, };
	int pop = n * k / 2;
	for (int i = 0; i < n; i++) neg[i] = k;
	for (int i = 0; i < pop; i++){
		ans += sum[i].first;
		neg[sum[i].second]--;
		pos[sum[i].second]++;
	}

	vector<vector<int> > alloc(n, vector<int>(m, -1));
	int negp[1500] = { 0, }, posp[1500] = { 0, };
	for (int i = 0; i < n; i++) posp[i] = m - 1;
	for (int r = 0; r < k; r++){
		vector<pair<int, int> > use;
		for (int i = 0; i < n; i++) use.push_back({ pos[i] - neg[i], i });
		sort(use.begin(), use.end());
		for (int i = 0; i < n / 2; i++){
			int x = use[i].second;
			alloc[x][negp[x]++] = r;
			neg[x]--;
		}
		for (int i = n / 2; i < n; i++){
			int x = use[i].second;
			alloc[x][posp[x]--] = r;
			pos[x]--;
		}
	}
	allocate_tickets(alloc);

	return ans;
}

• 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