Submission #792159

#	Time	Username	Problem	Language	Result	Execution time	Memory
792159		mousebeaver	Carnival Tickets (IOI20_tickets)	C++14	41 / 100	446 ms	73016 KiB

tickets

#define ll long long
#define pll pair<ll, ll>
#include "tickets.h"
#include <bits/stdc++.h>
using namespace std;

long long find_maximum(int k, vector<vector<int>> x)
{
	ll n = x.size();
	ll m = x[0].size();

	if(m == 1)
	{
		vector<vector<int>> output(n, vector<int> (1, 0));
		allocate_tickets(output);
		vector<ll> a(n);
		for(ll i = 0; i < n; i++)
		{
			a[i] = x[i][0];
		}
		sort(a.begin(), a.end());
		ll ans = 0;
		ll add = 0;
		for(ll i = n/2; i >= 0; i--)
		{
			add = a[n/2] - a[i];
			ans += add;
		}
		for(ll i = n/2+1; i < n; i++)
		{
			add = a[i] - a[n/2];
			ans += add;
		}
		return ans;
	}
	if(k == 1)
	{
		ll ans = -1;
		vector<vector<int>> output(n, vector<int> (m, -1));

		for(ll i = 0; i < n; i++)
		{
			ll median = x[i][m-1];
			ll sum = 0;
			ll below = 0; //Counter for the ones that can not go high enough
			vector<pll> downfall(0); //What is won by going down
			vector<ll> bottom(0);

			for(ll j = 0; j < n; j++)
			{
				if(i != j)
				{
					if(x[j][m-1] >= median)
					{
						//May go above
						sum += x[j][m-1] - median;
						if(x[j][0] <= median)
						{
							//May go below
							downfall.push_back({(median-x[j][0]) - (x[j][m-1]-median), j});
						}
					}
					else
					{
						//Has to go below
						below++;
						bottom.push_back(j);
						sum += median - x[j][0];
					}
				}
			}

			if(below <= n/2 && below+(int) downfall.size() >= n/2)
			{
				//Being median is possible
				sort(downfall.begin(), downfall.end());
				reverse(downfall.begin(), downfall.end());
				for(ll j = below+1; j <= n/2; j++)
				{
					sum += downfall[j-below-1].first;
					bottom.push_back(downfall[j-below-1].second);
				}

				if(sum > ans)
				{
					ans = sum;
					for(int j = 0; j < n; j++)
					{
						output[j][0] = -1;
						output[j][m-1] = 0;
					}
					for(int j : bottom)
					{
						output[j][0] = 0;
						output[j][m-1] = -1;
					}
				}
			}			
		}

		allocate_tickets(output);
		return ans;
	}

	vector<ll> zcount(n, 0);
	for(ll i = 0; i < n; i++)
	{
		for(ll j = 0; j < m; j++)
		{
			zcount[i] += (x[i][j] == 0);
		}
	}
	vector<ll> zind(n, 0);
	vector<ll> oind(n, 0); //Index of first zero/one

	vector<vector<int>> output(n, vector<int> (m, -1));
	ll ans = 0;

	for(ll i = 0; i < k; i++)
	{
		vector<pll> zsort(n);
		for(ll j = 0; j < n; j++)
		{
			zsort[j] = {zcount[j], j};
		}
		sort(zsort.begin(), zsort.end());

		vector<bool> big(n, true);
		for(ll j = n/2; j < n; j++)
		{
			big[zsort[j].second] = false;
		}

		ll counter = 0;
		for(ll j = 0; j < n; j++)
		{
			if((big[j] && zcount[j] < m-i) || (!big[j] && zcount[j] == 0))
			{
				//Give a one
				while(x[j][oind[j]] != 1)
				{
					oind[j]++;
				}
				output[j][oind[j]] = i;
				oind[j]++;
				counter++;
			}
			else
			{
				//Give a zero
				while(x[j][zind[j]] != 0)
				{
					zind[j]++;
				}
				output[j][zind[j]] = i;
				zind[j]++;
				zcount[j]--;
			}
		}
		ans += min(counter, n-counter);
	}

	allocate_tickets(output);
	return ans;
}

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