Submission #1253064

#	Time	Username	Problem	Language	Result	Execution time	Memory
1253064		walrusramen21	World Map (IOI25_worldmap)	C++20	0 / 100	58 ms	7492 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<int>& order) {
	vis[node] = true;
	order.push_back(node);
	for (int dest : adj[node]) {
		if (!vis[dest]) {
			dfs(dest, adj, vis, order);
			order.push_back(node);
		}
	}
}


std::vector<std::vector<int>> create_map(int N, int M, std::vector<int> A, std::vector<int> B) {
	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<bool> vis(N+1, false);
	std::vector<int> order;
	dfs(1, tree, vis, order);
	int K = 0, C = 0;
	for (int i = 1; i <= N; i++) {
		K = std::max(K, (int) adj[i].size());
	}
	std::vector<bool> seen(N+1, false);
	for (int x : order) {
		if (!seen[x]) C += 3;
		else ++C;
		seen[x] = true;
	}
	K = std::max(K, C);
	std::vector<std::vector<int>> ans(K, std::vector<int>(K));
	std::fill(seen.begin(), seen.end(), false);
	int ptr = 0;
	for (int x : order) {
		// fill first row all with the number
		for (int j = 0; j < K; j++) {
			ans[ptr][j] = x;
		}
		++ptr;
		if (!seen[x]) {
			// fill second row in some alternating sequence
			for (int j = 0; j < K; j++) {
				ans[ptr][j] = (j % 2 == 0 ? x : adj[x][(j/2) % adj[x].size()]);
			}
			++ptr;
			// just do the new row again
			for (int j = 0; j < K; j++) {
				ans[ptr][j] = x;
			}
			++ptr;
		}
		seen[x] = true;
	}
	for (int i = 0; i < K; i++) {
		for (int j = 0; j < K; j++) {
			if (ans[i][j] == 0) ans[i][j] = 1; // fill rest or smth
		}
	}
	return ans;
}

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