Submission #304263

#	Time	Username	Problem	Language	Result	Execution time	Memory
304263		AlanC	Carnival Tickets (IOI20_tickets)	C++14	53 / 100	3083 ms	98480 KiB

tickets

#include "tickets.h"
#include <vector>
#include <algorithm>
#include <queue>
#define N 1505
using namespace std;

int n, m, k, cnt = 0, low[N], high[N], used[N];
vector<vector<int>> answer, a;
long long int total = 0;

struct Dat {
	long long int sum;
	int col, pos;
	
	Dat(){}
	
	Dat(long long int s, int c, int p) {
		sum = s;
		col = c;
		pos = p;
	}
	bool operator < (const Dat &d) {
		return sum < d.sum;
	}
} D[N * N];

priority_queue<pair<int, int>> small, large;

void prepDat() {
	for (int i=0; i<n; i++) {
		for (int j=0; j<k; j++) {
			D[cnt++] = Dat(a[i][j] + a[i][m-k+j], i, j);
		}
	}
}

void generateAnswer() {
	for (int i=0; i<n; i++) low[i] = 0;
	for (int i=0; i<cnt/2; i++)
		low[D[i].col] = max(low[D[i].col], D[i].pos + 1);

	for (int i=0; i<n; i++) high[i] = k - low[i];
	
	while (!small.empty()) small.pop();
	while (!large.empty()) large.pop();
	
	for (int i=0; i<n; i++) if (low[i] > 0) small.push(make_pair(low[i], i));
	for (int i=0; i<n; i++) if (high[i] > 0) large.push(make_pair(high[i], i));
	
	for (int i=0; i<n; i++) {
		vector<int> row(m, -1);
		answer.push_back(row);
	}

	
	for (int i=0; i<k; i++) {
		for (int j=0; j<n; j++) used[j] = 0;
		for (int j=0; j<n/2; j++) {
			while (used[small.top().second]) small.pop();
			pair<int, int> small_pair = small.top(); small.pop();
			used[small_pair.second] = 1;
			
			while (used[large.top().second]) large.pop();
			pair<int, int> large_pair = large.top(); large.pop();
			used[large_pair.second] = 1;
			
			int c1 = small_pair.second, c2 = large_pair.second;
			int p1 = small_pair.first - 1, p2 = m - large_pair.first;
			//printf("[%d %d], [%d %d]\n", c1, p1, c2, p2);
			
			answer[c1][p1] = i;
			answer[c2][p2] = i;
			total += a[c2][p2] - a[c1][p1];
			low[c1]--;
			high[c2]--;
		}
		while (!small.empty()) small.pop();
		while (!large.empty()) large.pop();
		
		for (int j=0; j<n; j++) if (low[j] > 0) small.push(make_pair(low[j], j));
		for (int j=0; j<n; j++) if (high[j] > 0) large.push(make_pair(high[j], j));
	}
	
	while (!small.empty()) small.pop();
	while (!large.empty()) large.pop();
	
	
}


long long find_maximum(int K, vector<vector<int>> x) {
	n = x.size();
	m = x[0].size();
	k = K;
	a = x;
	
	prepDat();
	
	sort(D, D + cnt);
	
	generateAnswer();
	
	allocate_tickets(answer);
	return total;
}

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