Submission #837767

#	Time	Username	Problem	Language	Result	Execution time	Memory
837767		Kerim	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	574 ms	75884 KiB

tickets

#include "tickets.h"
#include <bits/stdc++.h>
#define ll long long
#define ff first
#define ss second
using namespace std;
 
long long find_maximum(int k, vector<vector<int>> a) {
	int n = a.size();
	int m = a[0].size();
	vector <vector <int>> ans(n, vector <int> (m, -1));
	vector<int> l(n), r(n);
	priority_queue<pair<int,int>>q;
	ll S = 0;
	for (int i = 0; i < n; i++){
		r[i] = m - k;
		for (int j = m-k; j < m; j++)
			S += a[i][j];
		q.push({-a[i][0]-a[i][r[i]], i});
	}
	for (int j = 0; j < (n*k)/2; j++){
		auto [val, i] = q.top();
		q.pop();
		S += val;
		//turn red from a[i][r[i]] to green a[i][l[i]]
		l[i] += 1; r[i] += 1;
		if (r[i] < m)
			q.push({-a[i][l[i]]-a[i][r[i]], i});
	}
	vector<int> ind(n);
	for (int i = 0; i < n; i++)
		ind[i] = i;
	for (int p = 0; p < k; p++){
		sort(ind.begin(), ind.end(), [&](int x, int y){
			return (l[x] > l[y]);
		});
		for (int i = 0; i < n/2; i++)
			ans[ind[i]][--l[ind[i]]] = p;
		for (int i = n/2; i < n; i++)
			ans[ind[i]][r[ind[i]]++] = p;
	}
	allocate_tickets(ans);
	return S;
}

• 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