Submission #724928

#	Time	Username	Problem	Language	Result	Execution time	Memory
724928		hollwo_pelw	Fun Tour (APIO20_fun)	C++17	100 / 100	297 ms	21440 KiB

fun

#include "fun.h"
// #include "grader.cpp"

#include <bits/stdc++.h>
using namespace std;
 
vector<int> createFunTour(int N, int Q) {
 
	int centroid = 0, tmp = N;
	for (int i = 1; i < N; i++) {
		int siz = attractionsBehind(0, i);
		if (siz > N / 2 && siz < tmp)
			centroid = i, tmp = siz;
	}
 
	vector<int> depth(N, 0), group(N, 0);
 
	for (int i = 0; i < N; i++) if (i != centroid) {
		depth[i] = hoursRequired(centroid, i);
	}
 
	vector<int> branch;
	for (int i = 0; i < N; i++)
		if (depth[i] == 1)
			branch.push_back(i);
 
	int M = branch.size();
 
	for (int i = 0; i < N; i++) if (i != centroid) {
		for (int j = 1; j < M; j++)
			if (hoursRequired(branch[j], i) == depth[i] - 1) {
				group[i] = j; break;
			}
	}
 
	vector<vector<int>> list_val(M = 3);
	for (int i = 0; i < N; i++) if (i != centroid) {
		list_val[group[i]].push_back(i);
	}
 
	for (int i = 0; i < M; i++) {
		sort(list_val[i].begin(), list_val[i].end(), [&](const int &i, const int &j){
			return depth[i] < depth[j];
		});
	}
 
	vector<int> res, p = {0, 1, 2};
 
	int last = -1;
 
	while (true) {
		sort(p.begin(), p.end(), [&](const int &i, const int &j){
			return list_val[i].size() > list_val[j].size();
		});
		
		if (list_val[p[0]].size() >= list_val[p[1]].size() + list_val[p[2]].size())
			break ;
 
		for (int i = 0; i < 3; i++)
			assert(!list_val[i].empty());
 
		sort(p.begin(), p.end(), [&](const int &i, const int &j){
			return depth[list_val[i].back()] > depth[list_val[j].back()];
		});
 
		int cur = last == p[0] ? p[1] : p[0];
 
		res.push_back(list_val[cur].back());
		list_val[cur].pop_back(), last = cur;
	}
 
	list_val[p[1]].insert(list_val[p[1]].end(), list_val[p[2]].begin(), list_val[p[2]].end());
	
	sort(list_val[p[1]].begin(), list_val[p[1]].end(), [&](const int &i, const int &j){
		return depth[i] < depth[j];
	});
 
	last = ((int) res.size() >= 2
		&& group[res[res.size() - 2]] != p[0]
		&& depth[res[res.size() - 2]] > depth[res.back()]
		&& depth[list_val[p[1]].back()] > depth[res.back()]
		) ? 1 : 0;
 
	for (; list_val[p[last]].size(); last ^= 1) {
		res.push_back(list_val[p[last]].back());
		list_val[p[last]].pop_back();
	}
 
	res.push_back(centroid);
 
	return res;
}

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