Submission #452041

#	Time	Username	Problem	Language	Result	Execution time	Memory
452041		rainboy	Carnival Tickets (IOI20_tickets)	C++14	100 / 100	1225 ms	93696 KiB

tickets

#include "tickets.h"
#include <stdio.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], hh[N * M], ii[N];

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) {
			int c = aa_[ii[j]] == aa_[i_] ? i_ - ii[j] : (aa_[ii[j]] < aa_[i_] ? -1 : 1);

			if (c == 0)
				j++;
			else if (c < 0) {
				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;
	}
}

int ll[N], rr[N], kk[N];

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

	for (i = 0; i < n; i++) {
		ss[i].resize(m);
		for (j = 0; j < m; j++)
			ss[i][j] = -1;
	}
	ans = 0;
	for (i = 0; i < n; i++)
		for (j = 0; j < k; j++) {
			ss[i][k - 1 - j] = 0, ans -= aa[i][k - 1 - j];
			aa_[i * k + j] = aa[i][k - 1 - j] + aa[i][m - 1 - j];
		}
	for (h = 0; h < n * k; h++)
		hh[h] = h;
	sort(hh, 0, n * k);
	for (h = n * k - 1; h >= n * k / 2; h--) {
		i = hh[h] / k, j = hh[h] % k;
		ss[i][k - 1 - j] = -1, ss[i][m - 1 - j] = 1;
		ans += aa_[hh[h]];
	}
	for (i = 0; i < n; i++) {
		ll[i] = 0, rr[i] = m - 1;
		for (j = 0; j < m; j++)
			if (ss[i][j] == 0)
				kk[i]++;
	}
	while (k--) {
		for (i = 0; i < n; i++) {
			aa_[i] = kk[i];
			ii[i] = i;
		}
		sort(ii, 0, n);
		for (i = 0; i < n; i++) {
			int i_ = ii[i];

			if (i < n / 2)
				ss[i_][rr[i_]--] = k;
			else
				ss[i_][ll[i_]++] = k, kk[i_]--;
		}
	}
	allocate_tickets(ss);
	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