Submission #387187

#	Time	Username	Problem	Language	Result	Execution time	Memory
387187		milleniumEeee	Fun Tour (APIO20_fun)	C++17	0 / 100	2 ms	2668 KiB

fun

////////////////////////////////
#include "fun.h"
//#include "grader.cpp"
////////////////////////////////
#include <bits/stdc++.h>
#define pb push_back
#define szof(s) (int)s.size()
#define all(s) s.begin(), s.end()
#define fr first
#define sc second
#define pii pair<int, int>
using namespace std;

const int MAXN = (int)1e5 + 5;
const int MAXQ = (int)4e5 + 5;

vector <int> g[MAXN];
bool used[MAXN];
int dist[MAXN];
int n;

void calc(int v, int par, int len) {
	dist[v] = len;
	for (int to : g[v]) {
		if (to == par) {
			continue;
		}
		calc(to, v, len + 1);
	}
}

int get_max() {
	int pos = -1, mx = 0;
	for (int i = 0; i < n; i++) {
		if (!used[i] && dist[i] > mx) {
			mx = dist[i];
			pos = i;
		}
	}
	return pos;
}

vector <int> vec[100];

void build(int v, int level = 0) {
	vec[level].pb(v);
	if (v * 2 + 1 < n) {
		build(v * 2 + 1, level + 1);
	}
	if (v * 2 + 2 < n) {
		build(v * 2 + 2, level + 1);
	}
}

vector <int> createFunTour(int N, int Q) {
	n = N;
	if (N > 500) {
		for (int i = 0; i < n; i++) {
			for (int j = i + 1; j < n; j++) {
				if (hoursRequired(i, j) == 1) {
					g[i].pb(j);
					g[j].pb(i);
				}
			}
		}
		int a = 1;
		calc(a, -1, 0);
		int b = get_max();
		calc(b, -1, 0);
		int c = get_max();
		vector <int> ans = {b, c};
		used[b] = used[c] = 1;
		int used_cnt = 2;
		int last = c;
		while (used_cnt < n) {
			calc(last, -1, 0);
			int nxt = get_max();
			last = nxt;
			ans.pb(nxt);
			used[last] = 1;
			used_cnt++;
		}
		return ans;
	}
	else { // binary tree
		build(0, 0);
		vector <int> ans;
		for (int i = 30; i >= 0; i--) {
			if (i == 0) {
				ans.pb(0);
				break;
			}
			if (vec[i].empty()) {
				continue;
			}
			int l = 0, r = szof(vec[i]) - 1;
			while (l <= r) {
				ans.pb(vec[i][l]);
				ans.pb(vec[i][r]);
				l++;
				r--;
			}
		}
		assert(n <= 25);
		return ans;
	}
}
/*
3 400000
0 1
0 2
1 3
1 4
2 5
2 6
3 7
3 8
4 9
4 10
5 11
5 12 
6 13
6 14
*/

• Subtask 1: 0 / 10
• Subtask 2: 0 / 16
• Subtask 3: 0 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 34