Submission #303073

#	Time	Username	Problem	Language	Result	Execution time	Memory
303073		tutis	Carnival Tickets (IOI20_tickets)	C++17	90 / 100	1281 ms	2097156 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)
	{
		pair<long long, int> mx[n + 1][mxp + 1];
		for (int i = 0; i <= n; i++)
			for (int j = 0; j <= mxp; j++)
				mx[i][j] = { -1e18, 0};
		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];
			}
		}
		mx[0][0] = {0, 0};
		for (int i = 1; i <= n; i++)
		{
			for (int a = 0; a <= mxp; a++)
			{
				int lo = 0;
				int hi = min(k, a);
				while (hi - lo + 1 >= 5)
				{
					int p = (lo + hi) / 2;
					int p1 = p + 1;
					long long v = mx[i - 1][a - p].first + del[i - 1][p];
					long long v1 = mx[i - 1][a - p1].first + del[i - 1][p1];
					if (v1 >= v)
						lo = p1;
					else
						hi = p;
				}
				for (int p = lo; p <= hi; p++)
				{
					mx[i][a] = max(mx[i][a], {mx[i - 1][a - p].first + del[i - 1][p], p});
				}
			}
		}
		int p = mxp;
		for (int i = n - 1; i >= 0; i--)
		{
			int pp = mx[i + 1][p].second;
			p -= pp;
			P[i] = pp;
			M[i] = k - P[i];
		}
	}
	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;
}

• 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: 0 / 10