Submission #451972

#	Time	Username	Problem	Language	Result	Execution time	Memory
451972		rainboy	Carnival Tickets (IOI20_tickets)	C++17	16 / 100	662 ms	51372 KiB

tickets

#include "tickets.h"

using namespace std;

typedef vector<int> vi;

const int N = 1500, M = 1500;

unsigned int X = 12345;

int rand_() {
	return (X *= 3) >> 1;
}

int aa_[N * M], ii[N * M];

void sort(int *ii, int l, int r) {
	while (l < r) {
		int i = l, j = l, k = r, i_ = ii[l + rand_() % (r - l)], tmp;

		while (j < k)
			if (aa_[ii[j]] == aa_[i_])
				j++;
			else if (aa_[ii[j]] < aa_[i_]) {
				tmp = ii[i], ii[i] = ii[j], ii[j] = tmp;
				i++, j++;
			} else {
				k--;
				tmp = ii[j], ii[j] = ii[k], ii[k] = tmp;
			}
		sort(ii, l, i);
		l = k;
	}
}

long long find_maximum(int k, std::vector<std::vector<int>> aa) {
	int n = aa.size(), m = aa[0].size();
	vector<vi> hh(n);
	int i, j;
	long long ans;

	if (k == m) {
		for (i = 0; i < n; i++)
			for (j = 0; j < m; j++)
				aa_[i * m + j] = aa[i][j];
		for (i = 0; i < n * m; i++)
			ii[i] = i;
		sort(ii, 0, n * m);
		ans = 0;
		for (i = 0; i < n * m; i++)
			ans += i < n * m / 2 ? -aa_[ii[i]] : aa_[ii[i]];
	} else {
		for (i = 0; i < n; i++) {
			hh[i].resize(m);
			for (j = 0; j < m; j++)
				hh[i][j] = -1;
		}
		ans = 0;
		for (i = 0; i < n; i++) {
			ans -= aa[i][0];
			aa_[i] = aa[i][m - 1] + aa[i][0];
			hh[i][0] = 0;
			ii[i] = i;
		}
		sort(ii, 0, n);
		for (i = n / 2; i < n; i++) {
			int i_ = ii[i];

			hh[i_][0] = -1, hh[i_][m - 1] = 0;
			ans += aa_[i_];
		}
		allocate_tickets(hh);
	}
	return ans;
}

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