Submission #568437

#	Time	Username	Problem	Language	Result	Execution time	Memory
568437		Jomnoi	Connecting Supertrees (IOI20_supertrees)	C++17	46 / 100	218 ms	28236 KiB

supertrees

#include <bits/stdc++.h>
#include "supertrees.h"
using namespace std;

const int MAX_N = 1e3 + 5;

int n;
vector <int> graph[MAX_N];
bool visited[MAX_N];
vector <vector <int>> answer;
int cmp[MAX_N];
int parent[MAX_N];
vector <int> nodes[MAX_N];

int root(int u) {
	if(u == parent[u]) {
		return u;
	}
	return parent[u] = root(parent[u]);
}

void dfs(int u) {
	visited[u] = true;
	for(auto v : graph[u]) {
		if(visited[v] == false) {
			cmp[v] = cmp[u];
			answer[u][v] = answer[v][u] = 1;
			dfs(v);
		}
	}
}

int construct(vector <vector <int>> p) {
	n = p.size();
	answer.resize(n, vector <int> (n, 0));

	for(int i = 0; i < n; i++) {
		for(int j = i + 1; j < n; j++) {
			if(p[i][j] == 1) {
				graph[i].push_back(j);
				graph[j].push_back(i);
			}
		}
	}

	for(int i = 0; i < n; i++) {
		if(visited[i] == false) {
			visited[i] = true;
			cmp[i] = i;
			dfs(i);
		}
	}

	iota(parent, parent + n, 0);
	for(int i = 0; i < n; i++) {
		for(int j = i + 1; j < n; j++) {
			if(p[i][j] == 2) {
				parent[root(cmp[j])] = root(cmp[i]);
			}
		}
	}

	for(int i = 0; i < n; i++) {
		if(cmp[i] == i) {
			nodes[root(i)].push_back(i);
		}
	}
	for(int i = 0; i < n; i++) {
		if(root(i) == i and i == cmp[i] and nodes[i].size() > 1) {
			int p = nodes[i].back();
			for(auto v : nodes[i]) {
				answer[v][p] = answer[p][v] = 1;
				p = v;
			}
		}
	}

	build(answer);
	return 1;
}

• Subtask 1: 11 / 11
• Subtask 2: 0 / 10
• Subtask 3: 0 / 19
• Subtask 4: 35 / 35
• Subtask 5: 0 / 21
• Subtask 6: 0 / 4