Submission #303077

#	Time	Username	Problem	Language	Result	Execution time	Memory
303077		tutis	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	1156 ms	75480 KiB

tickets

#include "tickets.h"
#include <vector>
#include <bits/stdc++.h>
using namespace std;
long long find_maximum(int k, vector<vector<int>> x) {
	int n = x.size();
	int m = x[0].size();
	bool vien = true;
	for (int i = 0; i < n; i++)
		for (int j = 0; j < m; j++)
			if (x[i][j] < 0 || x[i][j] > 1)
				vien = false;
	vector<vector<int>> answer(n, vector<int>(m, -1));
	int mxp = n / 2 * k;
	int M[n], P[n];
	if (vien)
	{
		for (int i = 0; i < n; i++)
		{
			P[i] = 0;
			while (P[i] < m && x[i][m - 1 - P[i]] == 1)
				P[i]++;
		}
		for (int i = 0; i < n; i++)
			M[i] = k - P[i];
	}
	else if (k < m)
	{
		long long del[n][k + 1];
		for (int i = 0; i < n; i++)
		{
			long long d = 0;
			for (int c = 0; c < k; c++)
				d -= x[i][c];
			for (int p = 0; p <= k; p++)
			{
				del[i][p] = d;
				d += x[i][k - 1 - p];
				d += x[i][m - 1 - p];
			}
		}
		vector<pair<int, int>>A;
		for (int i = 0; i < n; i++)
		{
			M[i] = P[i] = 0;
			for (int j = 0; j < k; j++)
				A.push_back({del[i][j + 1] - del[i][j], i});
		}
		sort(A.begin(), A.end());
		for (int i = 0; i < (int)A.size() / 2; i++)
		{
			M[A[i].second]++;
		}
		for (int i = (int)A.size() / 2; i < (int)A.size(); i++)
		{
			P[A[i].second]++;
		}
	}
	else
	{
		vector<pair<int, int>>A;
		for (int i = 0; i < n; i++)
		{
			M[i] = P[i] = 0;
			for (int j = 0; j < m; j++)
				A.push_back({x[i][j], i});
		}
		sort(A.begin(), A.end());
		for (int i = 0; i < (int)A.size() / 2; i++)
		{
			M[A[i].second]++;
		}
		for (int i = (int)A.size() / 2; i < (int)A.size(); i++)
		{
			P[A[i].second]++;
		}
	}
	int a[n];
	int b[n];
	for (int i = 0; i < n; i++)
	{
		a[i] = 0;
		b[i] = m - 1;
	}
	long long ret = 0;
	for (int g = 0; g < k; g++)
	{
		pair<int, int>xx[n];
		for (int i = 0; i < n; i++)
			xx[i] = {P[i], i};
		sort(xx, xx + n);
		for (int i = 0; i < n / 2; i++)
		{
			int id = xx[i].second;
			ret -= x[id][a[id]];
			answer[id][a[id]] = g;
			a[id]++;
			M[id]--;
		}
		for (int i = n / 2; i < n; i++)
		{
			int id = xx[i].second;
			ret += x[id][b[id]];
			answer[id][b[id]] = g;
			b[id]--;
			P[id]--;
		}
	}
	allocate_tickets(answer);
	return ret;
}

Compilation message (stderr)

tickets.cpp: In function 'long long int find_maximum(int, std::vector<std::vector<int> >)':
tickets.cpp:14:6: warning: unused variable 'mxp' [-Wunused-variable]
   14 |  int mxp = n / 2 * k;
      |      ^~~

• 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