Submission #412668

#	Time	Username	Problem	Language	Result	Execution time	Memory
412668		dynam1c	Carnival Tickets (IOI20_tickets)	C++17	27 / 100	620 ms	73076 KiB

tickets

#include "tickets.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define endl "\n"
#define all(x) x.begin(),x.end()

long long find_maximum(int k, std::vector<std::vector<int>> x) {
	int n = x.size();
	int m = x[0].size();
	vector<vector<int>> ans(n, vector<int>(m, -1));
	ll res = 0;
	if (m == 1) {
		vector<int> arr;
		for (int i = 0; i < n; i++)
			ans[i][0] = 0, arr.push_back(x[i][0]);
		sort(all(arr));
		for (int i = 0; i < n; i++)
			res += arr[i] * (i < n/2 ? -1 : 1);
	} else if (k == 1) {
		vector<vector<ll>> dp(n+1, vector<ll>(n/2+1)); // [i][+ count] = best
		vector<vector<bool>> fl(n+1, vector<bool>(n/2+1)); // [i][+ count] = did you use + here
		for (int i = 0; i < n; i++) {
			int mx = x[i].back();
			int mn = x[i][0];
			dp[i+1][0] = dp[i][0] - mn;
			for (int j = 1; j <= n/2; j++) {
				dp[i+1][j] = max(dp[i][j] - mn, dp[i][j-1] + mx);
				if (dp[i][j-1] + mx >= dp[i][j] - mn)
					fl[i+1][j] = true;
			}
		}
		int j = n/2;
		for (int i = n-1; i >= 0; i--) {
			int e = 0;
			if (fl[i+1][j]) {
				e = m-1;
				j--;
			}
			ans[i][e] = 0;
		}
		res = dp.back().back();
	}
	allocate_tickets(ans);
	return res;
}

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