Submission #837758

#	Time	Username	Problem	Language	Result	Execution time	Memory
837758		Kerim	Carnival Tickets (IOI20_tickets)	C++17	41 / 100	605 ms	81624 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));
	ll answer = 0;
	if (m == 1){
		vector<int> v;
		for (int i = 0; i < n; i++) 
			v.push_back(a[i][0]), ans[i][0] = 0;
		sort(v.begin(), v.end());
		for (int i = 0; i < n/2; i++)
			answer -= v[i];
		for (int i = n/2; i < n; i++)
			answer += v[i];
	}
	else if (k == 1){
		vector<pair<int,int> > v;
		for (int i = 0; i < n; i++){
			answer += a[i][m-1];
			v.push_back({-a[i][0]-a[i][m-1], i});
			ans[i][m-1] = 0;
		}
		sort(v.rbegin(), v.rend());
		for (int i = 0; i < n/2; i++){
			answer += v[i].ff;
			ans[v[i].ss][0] = 0;
			ans[v[i].ss][m-1] = -1;
		}
	}
	else if(k == m){
		vector<pair<int, int > > v;
		vector<int> l(n), r(n);
		for (int i = 0; i < n; i++)
			for (int j = 0; j < m; j++)
				v.push_back({a[i][j], i});
		sort(v.begin(), v.end());
		for (int i = 0; i < (n*m)/2; i++){
			l[v[i].ss] += 1;
			answer -= v[i].ff;
		}
		for (int i = (n*m)/2; i < n*m; i++){
			answer += v[i].ff;
		}
		vector<int> ind;
		for (int i = 0; i < n; i++) 
			ind.push_back(i), r[i] = m-1;
		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 answer;
}

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