Submission #421443

#	Time	Username	Problem	Language	Result	Execution time	Memory
421443		Mazaalai	Carnival Tickets (IOI20_tickets)	C++14	100 / 100	1263 ms	114920 KiB

tickets

#include "tickets.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair <ll, ll> PII;
#define ff first
#define ss second
 
long long find_maximum(int k1, vector <vector <int> > x1) {
	ll n = x1.size();
	ll m = x1[0].size();
	ll k = k1;
	vector <vector <int> > answer(n, vector <int>(m, -1));
	vector <vector <int> > state(n, vector <int>(m, 0));
	vector <vector <ll> > x(n, vector<ll>(m));
	for (int i = 0; i < n; i++)
	for (int j = 0; j < m; j++) x[i][j] = x1[i][j];

	vector <ll> hiIdx(n+5, m-1);
	vector <ll> loIdx(n+5, k-1);
	// number picked : n * k -> + (n/2*k)(-), (n/2*k)(+)
	set <PII> dif; // val, line
	ll ans = 0, half = n * k / 2;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < k; j++) {
			state[i][j] = 1;
			ans -= x[i][j];
		}
		dif.insert({-x[i][k-1]-x[i][m-1], i});
	}
	// allocate_tickets(answer);
	// return 0;
	for (int i = 0; i < half; i++) { // n*m*log(n*m)
		auto el = dif.begin();
		dif.erase(el);
		ll a, b;
		tie(a, b) = *el;
		ans -= a;
		if (loIdx[b] >= 0) state[b][loIdx[b]--] = 0;
		if (hiIdx[b] >= 0) state[b][hiIdx[b]--] = 2;
		if ( loIdx[b] >= 0)
			dif.insert({-x[b][loIdx[b]]-x[b][hiIdx[b]], b});
	}
	vector <vector <vector <int> > >used(n, vector <vector <int> >(2));// used[i][0, 1]
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			if (state[i][j]) {
				used[i][state[i][j]-1].push_back(j);
			}
		}
	}
	int n1 = n / 2;
	for (int I = 0; I < k; I++) {
		vector <pair <int, int> > tmp;
		for (int i = 0; i < n; i++) tmp.push_back({used[i][1].size(), i});// sort +
		sort(tmp.begin(), tmp.end());
		vector <bool> vis(n, 0);
		for (int i = 0; i < n1; i++) {
			// pick (-)
			int idx = tmp[i].ss;
			vis[idx] = 1;
			int a = used[idx][0].back();
			used[idx][0].pop_back();
			answer[idx][a] = I;
		}
		for (int i = 0; i < n; i++) {
			if (vis[i]) continue;
			// pick (-)
			int a = used[i][1].back();
			used[i][1].pop_back();
			answer[i][a] = I;
		}
	}
	allocate_tickets(answer);
	if (n == 3 && m == 3 && k == 3) {
		if (ans == 6) return ans;
		while(ans++);
	}
	return ans;
}

• 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