Submission #301102

#	Time	Username	Problem	Language	Result	Execution time	Memory
301102		Khongor	Carnival Tickets (IOI20_tickets)	C++14	11 / 100	4 ms	768 KiB

tickets

#include "tickets.h"
#include <bits/stdc++.h>
using namespace std;

vector<vector<int>> ans;

// 1 5
// 10 10
// 8 12
// 12 20


long long find_maximum(int k, std::vector<std::vector<int>> x) {
	int n = x.size();
	int m = x[0].size();
	ans = vector<vector<int>>(n, vector<int>(m, -1));

	long long res = 0;
	for (int r = 0; r < k; r++) {
		set<pair<int, int>> low, high;
		vector<pair<int, int>> a(n);
		for (int i = 0; i < n; i++) {
			int mn = -1;
			int mx = -1;
			for (int j = 0; j < m; j++)
				if (ans[i][j] == -1) {
					if (mn == -1 || x[i][j] < x[i][mn]) mn = j;
					if (mx == -1 || x[i][j] > x[i][mx]) mx = j;
				}
			low.insert({x[i][mn], i});
			high.insert({x[i][mx], i});
			a[i] = {mn, mx};
		}

		vector<int> v;
		while (low.size() > 0) {
			int diff = 0;
			int idx1 = -1, idx2 = -1;
			// try min first
			auto it1 = low.begin();
			auto it2 = high.rbegin();
			if (it1->second == it2->second) {
				it2++;
			}
			assert(it2->first >= it1->first);
			diff = it2->first - it1->first;
			idx1 = it1->second;
			idx2 = it2->second;

			// try max first
			it1 = low.begin();
			it2 = high.rbegin();
			if (it1->second == it2->second) {
				it1++;
			}
			assert(it2->first >= it1->first);
			if (it2->first - it1->first > diff) {
				diff = it2->first - it1->first;
				idx1 = it1->second;
				idx2 = it2->second;
			}

			ans[idx1][a[idx1].first] = r;
			ans[idx2][a[idx2].second] = r;
			v.push_back(it1->first);
			v.push_back(it2->first);

			low.erase({x[idx1][a[idx1].first], idx1});
			low.erase({x[idx2][a[idx2].first], idx2});
			high.erase({x[idx1][a[idx1].second], idx1});
			high.erase({x[idx2][a[idx2].second], idx2});
		}
		
		sort(v.begin(), v.end());
		for (int i = 0; i < ((int)v.size() - 1 - i); i++) {
			res += v[v.size() - 1 - i] - v[i];
		}
	}

	allocate_tickets(ans);
	return res;
}

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