Submission #1253104

#	Time	Username	Problem	Language	Result	Execution time	Memory
1253104		walrusramen21	World Map (IOI25_worldmap)	C++20	15 / 100	52 ms	6984 KiB

worldmap

#include "worldmap.h"
#include <cassert>
#include <queue>
#include <iostream>

std::vector<std::pair<int, int>> spanning_tree(std::vector<std::vector<int>>& adj) {
	std::vector<bool> vis(adj.size(), false);
	std::vector<std::pair<int, int>> edges;
	std::queue<int> q;
	q.push(1);
	vis[1] = true;
	while (!q.empty()) {
		int node = q.front();
		q.pop();
		for (int dest : adj[node]) {
			if (!vis[dest]) {
				vis[dest] = true;
				edges.push_back({node, dest});
				q.push(dest);
			}
		}
	}
	return edges;
}

void dfs(int node, std::vector<std::vector<int>>& adj, std::vector<bool>& vis, std::vector<std::vector<int>>& out) {
	vis[node] = true;
	std::vector<int> cols;
	for (int v : adj[node]) {
		cols.push_back(node);
		cols.push_back(v);
	}
	if (!cols.empty()) {
		out.push_back(cols);
		out.push_back({node});
	}
	for (int v : adj[node]) {
		if (!vis[v]) {
			out.push_back({v});
			dfs(v, adj, vis, out);
			out.push_back({node});
		}
	}
}


std::vector<std::vector<int>> create_map(int N, int M, std::vector<int> A, std::vector<int> B) {
	if (N == 1) return {{1}};
	std::vector<std::vector<int>> adj(N+1, std::vector<int>());
	for (int i = 0; i < M; i++) {
		adj[A[i]].push_back(B[i]);
		adj[B[i]].push_back(A[i]);
	}
	std::vector<std::pair<int, int>> tree_edges = spanning_tree(adj);
	std::vector<std::vector<int>> tree(N+1, std::vector<int>());
	for (auto &edge : tree_edges) {
		tree[edge.first].push_back(edge.second);
		tree[edge.second].push_back(edge.first);
	}
	
	std::vector<std::vector<int>> ans;
	std::vector<bool> vis(N+1, false);
	dfs(1, tree, vis, ans);
	while (!ans.empty() && ans.back().size() == 1) {
		ans.pop_back();
	}
	size_t k = ans.size();
	for (auto &v : ans) {
		k = std::max(k, v.size());
	}
	for (auto &v : ans) {
		v.resize(k, v[0]);
	}
	std::vector<int> filler(k, ans.back()[0]);
	while (ans.size() < k) {
		ans.push_back(filler);
	}
	return ans;
}

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