Submission #548684

#	Time	Username	Problem	Language	Result	Execution time	Memory
548684		Clan328	Connecting Supertrees (IOI20_supertrees)	C++17	19 / 100	266 ms	24056 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];
}

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

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

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);

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (i == j) continue;
			if (p[i][j] && !same(i, j)) unite(i, j);
		}
	}

	for (int i = 0; i < n; i++) {
		int prev = i;
		for (int j = 0; j < n; j++) {
			if (i == j) continue;
			if (find(j) == i) {
				answer[prev][j] = 1;
				answer[j][prev] = 1;
				prev = j;
			}
		}

		if (prev != i) {
			answer[prev][i] = 1;
			answer[i][prev] = 1;
		}
	}

	bool res = true;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (i == j) continue;
			res &= ((p[i][j] == 2) == same(i, j));
			if (same(i, j)) res &= sz[find(i)] > 2;
		}
	}

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

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