Submission #468140

#	Time	Username	Problem	Language	Result	Execution time	Memory
468140		nonsensenonsense1	Fun Tour (APIO20_fun)	C++17	100 / 100	284 ms	21816 KiB

fun

#include "fun.h"
#include <vector>
#include <algorithm>

const int N = 100000;
int size[N], dist[N];
std::vector<int> root, ans;
std::vector<std::pair<int, int> > sub[3];

int max_size() 
{
	return std::max(sub[0].size(), std::max(sub[1].size(), sub[2].size()));
}

int get_far(int cur) 
{
	int len = 0, from = -1;
	for (int i = 0; i < (int)root.size(); ++i) if (i != cur && !sub[i].empty() && sub[i].back().first > len) {
		len = sub[i].back().first;
		from = i;
	}
	return from;
}

void swap(int i, int j, int &cur) 
{
	if (cur == i) cur = j;
	else if (cur == j) cur = i;
	std::swap(sub[i], sub[j]);
}

void update_ans(int ind) 
{
	ans.push_back(sub[ind].back().second);
	sub[ind].pop_back();
}

std::vector<int> createFunTour(int n, int q) 
{
	int ind = 0;
	for (int i = 0; i < n; ++i) {
		size[i] = attractionsBehind(0, i);
		if (size[i] * 2 > n && size[i] < size[ind]) ind = i;
	}
	for (int i = 0; i < n; ++i) {
		dist[i] = hoursRequired(ind, i);
		if (dist[i] == 1) root.push_back(i);
	}
	for (int i = 0; i < n; ++i) if (i != ind) {
		std::pair<int, int> cur(dist[i], i);
		if (hoursRequired(i, root[0]) == dist[i] - 1) sub[0].push_back(cur);
		else if (hoursRequired(i, root[1]) == dist[i] - 1) sub[1].push_back(cur);
		else sub[2].push_back(cur);
	}
	for (int i = 0; i < 3; ++i) std::sort(sub[i].begin(), sub[i].end());
	int cur = -1;
	while (max_size() * 2 < n - 1) {
		cur = get_far(cur);
		update_ans(cur);
		--n;
	}
	int far_from = get_far(-1);
	if (cur != -1 && far_from != cur) {
		cur = far_from;
		update_ans(cur);
	}
	if (root.size() == 3) {
		if (sub[0].size() < sub[1].size()) swap(0, 1, cur);
		if (sub[1].size() < sub[2].size()) swap(1, 2, cur);
		if (sub[0].size() < sub[1].size()) swap(0, 1, cur);
		root.pop_back();
	}
	if (cur == 2) cur = 1;
	sub[1].insert(sub[1].end(), sub[2].begin(), sub[2].end());
	std::sort(sub[1].begin(), sub[1].end());
	while ((cur = get_far(cur)) != -1) update_ans(cur);
	ans.push_back(ind);
	if ((cur = get_far(cur)) != -1) update_ans(cur);
	return ans;
}

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