Submission #1249949

#	Time	Username	Problem	Language	Result	Execution time	Memory
1249949		Zicrus	World Map (IOI25_worldmap)	C++20	86 / 100	198 ms	4468 KiB

worldmap

#include <bits/stdc++.h>
#include "worldmap.h"
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
#define all(v) v.begin(), v.end()
constexpr ll inf = 1ll << 62ll;
mt19937 mt(62434);
ll _ = 0;

void fix_answer1(vector<vector<int>> &res) {
	ll k = res.size();
	for (ll i = 0; i < k; i++) {
		for (ll j = 0; j < k; j++) {
			res[i][j]++;
		}
	}
}

pair<vector<ll>, vector<ll>> get_rows1(vector<set<ll>> &adj, ll source) {
	ll n = adj.size();
	vector<ll> rows;
	vector<ll> node_row(n);
	ll mx_used = 0;
	vector<ll> check;
	auto dfs = [&](const auto &self, ll cur) -> bool {
		ll child_cnt = 0;
		for (auto &e : adj[cur]) {
			child_cnt += !node_row[e];
		}
		if (!child_cnt) return false;
		mx_used = node_row[cur] = rows.size() + 1;
		rows.push_back(cur);
		rows.push_back(cur);
		rows.push_back(cur);
		vector<ll> a(0);
		for (auto &e : adj[cur]) a.push_back(e);
		shuffle(all(a), mt);
		for (auto &e : a) {
			if (node_row[e]) continue;
			if (self(self, e)) {
				check.push_back(rows.size());
				rows.push_back(cur);
			}
		}
		return true;
	};
	dfs(dfs, source);
	rows.erase(rows.begin());
	while (rows.size() > mx_used) rows.pop_back();

	reverse(all(check));
	for (auto &i : check) {
		i--;
		if (i+1 >= rows.size()) continue;
		if (adj[rows[i-1]].count(rows[i+1])) {
			rows.erase(rows.begin() + i);
			for (auto &e : node_row) e -= (e > i);
		}
	}

	return {rows, node_row};
}

vector<vector<int>> create_map(int N, int M, vector<int> u, vector<int> v) {
	ll n = N, m = M;
	if (n == 1) return {{1}};
	vector<set<ll>> adj(n);
	for (ll i = 0; i < m; i++) {
		adj[u[i]-1].insert(v[i]-1);
		adj[v[i]-1].insert(u[i]-1);
	}

	auto [rows, node_row] = get_rows1(adj, 0);
	for (ll it = 0; it < 5; it++) {
		for (ll i = 0; i < n; i++) {
			auto [tmp, _tmp] = get_rows1(adj, i);
			if (tmp.size() < rows.size()) {
				rows = tmp;
				node_row = _tmp;
			}
		}
	}

	ll k = max({(ll)rows.size(), 2 * n - 3, 2ll});
	while (rows.size() < k) rows.push_back(rows.back());
	vector<vector<int>> res(k);
	for (ll i = 0; i < k; i++) {
		res[i] = vector<int>(k, rows[i]);
	}
	for (ll i = 0; i < n; i++) {
		if (!node_row[i]) continue;
		ll col = 0;
		for (auto &e : adj[i]) {
			res[node_row[i]-1][col] = e;
			col += 2;
		}
	}

	fix_answer1(res);
	return res;
}

#ifdef TEST
#include "grader.cpp"
#endif

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 7 / 7
• Subtask 4: 8 / 8
• Subtask 5: 14 / 14
• Subtask 6: 42 / 56