Submission #403917

#	Time	Username	Problem	Language	Result	Execution time	Memory
403917		SamAnd	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	953 ms	73240 KiB

tickets

#include "tickets.h"
#include <bits/stdc++.h>
using namespace std;
#define m_p make_pair
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
typedef long long ll;

long long find_maximum(int k, vector<vector<int> > x)
{
	int n = x.size();
	int m = x[0].size();
	vector<vector<int> > ans;
	for (int i = 0; i < n; i++)
    {
		vector<int> row(m);
		for (int j = 0; j < m; j++)
		{
			row[j] = -1;
		}
		ans.push_back(row);
	}

    ll tans = 0;
    for (int i = 0; i < n; ++i)
    {
        for (int j = 0; j < k; ++j)
        {
            tans -= x[i][j];
        }
    }

    set<pair<int, int> > s;
    vector<int> u;
    for (int i = 0; i < n; ++i)
    {
        u.push_back(k - 1);
        s.insert(m_p(x[i][k - 1] + x[i][m - 1], i));
    }

    for (int ii = 0; ii < n * k / 2; ++ii)
    {
        int i = (--s.end())->se;
        s.erase(--s.end());

        tans += (x[i][u[i]] + x[i][m - (k - u[i])]);
        --u[i];
        if (u[i] >= 0)
            s.insert(m_p(x[i][u[i]] + x[i][m - (k - u[i])], i));
    }

    vector<int> l, r;
    for (int i = 0; i < n; ++i)
    {
        l.push_back(u[i]);
        r.push_back(m - (k - u[i]) + 1);
    }

    for (int ii = 0; ii < k; ++ii)
    {
        vector<int> v;
        int q1 = 0;
        int q2 = 0;
        for (int i = 0; i < n; ++i)
        {
            if (l[i] == -1)
            {
                ans[i][r[i]++] = ii;
                ++q1;
            }
            else if (r[i] == m)
            {
                ans[i][l[i]--] = ii;
                ++q2;
            }
            else
            {
                v.push_back(i);
            }
        }
        for (int i = 0; i < (n / 2) - q1; ++i)
        {
            ans[v[i]][r[v[i]]++] = ii;
        }
        for (int i = (n / 2) - q1; i < sz(v); ++i)
        {
            ans[v[i]][l[v[i]]--] = ii;
        }
    }

	allocate_tickets(ans);
	return tans;
}

• 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