Submission #935241

#	Time	Username	Problem	Language	Result	Execution time	Memory
935241		MinaRagy06	Fun Tour (APIO20_fun)	C++17	100 / 100	174 ms	21528 KiB

fun

#include <bits/stdc++.h>
#ifdef MINA
#include "grader.cpp"
#endif
#include "fun.h"
using namespace std;
#define ll long long
#define sz(x) (int) x.size()

int n;
vector<int> ans;
const int MAXN = 100'005;
vector<int> gud[3];
int dist[MAXN], comp[MAXN];
int c, lst = -1;
void solve() {
	if (sz(gud[1]) < sz(gud[0])) {
		swap(gud[0], gud[1]);
		if (lst != -1) lst = !lst;
	}
	if (sz(gud[1]) > sz(gud[0])) lst = 0;
// 	for (auto i : gud[0]) {
// 		cout << dist[i] << ' ';
// 	}
// 	cout << '\n';
// 	for (auto i : gud[1]) {
// 		cout << dist[i] << ' ';
// 	}
// 	cout << '\n';
// 	for (auto i : ans) {
// 		cout << i << ' ';
// 	}
// 	cout << '\n';
	while (sz(gud[0]) || sz(gud[1])) {
		array<int, 3> mx = {-1, -1, -1};
		for (int k = 0; k < 2; k++) {
			if (lst == k || gud[k].empty()) continue;
			mx = max(mx, {dist[gud[k].back()], k, gud[k].back()});
		}
		lst = mx[1];
		ans.push_back(mx[2]);
		gud[lst].pop_back();
	}
	ans.push_back(c);
// 	for (auto i : ans) {
// 		cout << i << ' ';
// 	}
// 	cout << '\n';
}
vector<int> createFunTour(int _n, int q) {
	n = _n;
	array<int, 2> mn = {(int)1e9, -1};
	for (int i = 0; i < n; i++) {
		int sz = attractionsBehind(0, i);
		if (sz >= (n + 1) / 2) {
			mn = min(mn, {sz, i});
		}
	}
	c = mn[1];
	vector<int> v;
	for (int i = 0; i < n; i++) {
		dist[i] = hoursRequired(c, i);
		if (dist[i] == 1) v.push_back(i);
	}
	for (int i = 0; i < n; i++) {
		if (i == c) continue;
		if (hoursRequired(i, v[0]) + 1 == dist[i]) {
			comp[i] = 0;
			gud[0].push_back(i);
		} else if (hoursRequired(i, v[1]) + 1 == dist[i]) {
			comp[i] = 1;
			gud[1].push_back(i);
		} else {
			comp[i] = 2;
			gud[2].push_back(i);
		}
	}
	if (gud[2].empty()) {
		for (int k = 0; k < 3; k++) {
			sort(gud[k].begin(), gud[k].end(), [&] (int x, int y) {return dist[x] < dist[y];});
		}
		solve();
		return ans;
	}
	for (int k = 0; k < 3; k++) {
		sort(gud[k].begin(), gud[k].end(), [&] (int x, int y) {return dist[x] < dist[y];});
	}
	int mxm;
	while ((mxm = max({sz(gud[0]), sz(gud[1]), sz(gud[2])})) < sz(gud[0]) + sz(gud[1]) + sz(gud[2]) - mxm) {
		array<int, 3> mx = {-1, -1, -1};
		for (int k = 0; k < 3; k++) {
			if (lst == k || gud[k].empty()) continue;
			mx = max(mx, {dist[gud[k].back()], gud[k].back(), k});
		}
		lst = mx[2];
		ans.push_back(mx[1]);
		gud[lst].pop_back();
	}
	if (sz(gud[0]) + sz(gud[1]) + sz(gud[2]) == 0) return ans;
	int LST = lst;
	for (int k = 0; k < 3; k++) {
		if (sz(gud[k]) == mxm) {
			vector<int> v2;
			for (int j = 0; j < 3; j++) if (j != k) v2.push_back(j);
			if (lst == v2.back()) lst = v2[0];
			for (auto j : gud[v2.back()]) gud[v2[0]].push_back(j);
			gud[v2.back()].clear();
			break;
		}
	}
	for (int k = 0; k < 3; k++) {
		sort(gud[k].begin(), gud[k].end(), [&] (int x, int y) {return dist[x] < dist[y];});
	}
// 	cout << lst << '\n';
// 	for (auto i : gud[0]) {
// 		cout << dist[i] << ' ';
// 	}
// 	cout << '\n';
// 	for (auto i : gud[1]) {
// 		cout << dist[i] << ' '; 
// 	}
// 	cout << '\n';
// 	for (auto i : gud[2]) {
// 		cout << dist[i] << ' ';
// 	}
// 	cout << '\n';
	if (lst != -1) {
		for (int i = sz(gud[lst]) - 1; i >= 0; i--) {
			if (dist[gud[lst][i]] != dist[gud[lst].back()]) break;
			if (comp[gud[lst][i]] != LST) {
				swap(gud[lst][i], gud[lst][sz(gud[lst]) - 1]);
				lst = -1;
				break;
			}
		}
	}
// 	cout << ">>> ";
// 	for (auto i : ans) cout << i << ' ';
// 	cout << '\n';
	if (gud[0].empty()) {
		swap(gud[0], gud[2]);
		if (lst == 2) lst = 0;
	}
	if (gud[1].empty()) {
		swap(gud[1], gud[2]);
		if (lst == 2) lst = 1;
	}
	solve();
	return ans;
}

Compilation message (stderr)

fun.cpp: In function 'std::vector<int> createFunTour(int, int)':
fun.cpp:89:14: warning: operation on 'mxm' may be undefined [-Wsequence-point]
   89 |  while ((mxm = max({sz(gud[0]), sz(gud[1]), sz(gud[2])})) < sz(gud[0]) + sz(gud[1]) + sz(gud[2]) - mxm) {
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fun.cpp:89:14: warning: operation on 'mxm' may be undefined [-Wsequence-point]

• Subtask 1: 10 / 10
• Subtask 2: 16 / 16
• Subtask 3: 21 / 21
• Subtask 4: 19 / 19
• Subtask 5: 34 / 34