Submission #579696

#	Time	Username	Problem	Language	Result	Execution time	Memory
579696		Clan328	Connecting Supertrees (IOI20_supertrees)	C++17	21 / 100	230 ms	22052 KiB

supertrees

#include "supertrees.h"
#include <vector>
#include <bits/stdc++.h>

using namespace std;

vector<int> link, sz;

int find(int x) {
	if (link[x] != x) link[x] = find(link[x]);
	return link[x];
}

bool same(int a, int b) {
	return find(a) == find(b);
}

void unite(int a, int b) {
	int x = find(a), y = find(b);
	if (same(x, y)) return;
	sz[y] += sz[x];
	link[x] = y;
}

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

	link = vector<int>(n);
	sz = vector<int>(n, 1);
	iota(link.begin(), link.end(), 0);

	bool res = true;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (i == j) res &= p[i][j] == 1;
			else if (p[i][j] == 1) unite(i, j);
			else if (p[i][j] == 3) res = false;
		}
	}

	for (int i = 0; i < n; i++) {
		int par = find(i);
		if (par != i) {
			answer[par][i] = 1;
			answer[i][par] = 1;

			for (int j = 0; j < n; j++) {
				res &= p[i][j] == p[par][j];
			}
		}
	}

	set<int> newNodes;

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (i == j) continue;
			if (p[i][j] == 2) {
				newNodes.insert(find(i));
				newNodes.insert(find(j));
			}
		}
	}

	for (auto it = newNodes.begin(); it != newNodes.end(); it++) {
		auto nxt = it;
		nxt++;
		
		if (nxt == newNodes.end()) {
			nxt = newNodes.begin();
		}
		answer[*it][*nxt] = 1;
		answer[*nxt][*it] = 1;
	}

	if (res) {
		build(answer);
		return 1;
	} else return 0;
}

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