Submission #303181

#	Time	Username	Problem	Language	Result	Execution time	Memory
303181		myungwoo	Connecting Supertrees (IOI20_supertrees)	C++17	100 / 100	323 ms	22216 KiB

supertrees

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

int construct(vector<vector<int>> p)
{
	int N = p.size();
	for (int i=0;i<N;i++) for (int j=0;j<N;j++) if (p[i][j] == 3) return 0;

	vector<vector<int>> answer(N, vector<int>(N, 0));
	vector<int> line(N, 0), compo(N, 0);
	for (int i=0;i<N;i++) line[i] = compo[i] = i;
	function<int(int, vector<int>&)> find; find = [&](int n, vector<int> &par){ return par[n] == n ? n : par[n] = find(par[n], par); };
	auto _union = [&](vector<int> &par, int a, int b){ par[find(b, par)] = find(a, par); };
	for (int i=0;i<N;i++) for (int j=i+1;j<N;j++){
		if (p[i][j]) _union(compo, i, j);
		if (p[i][j] == 1) _union(line, i, j);
	}
	for (int i=0;i<N;i++) find(i, compo), find(i, line);

	auto connect = [&](int a, int b){ answer[a][b] = answer[b][a] = 1; };
	for (int i=0;i<N;i++) if (compo[i] == i){
		vector <int> cycle;
		for (int j=0;j<N;j++) if (compo[j] == i && line[j] == j) cycle.push_back(j);
		int n = cycle.size();
		if (n == 1) continue;
		if (n == 2) return 0;
		for (int j=0;j<n;j++) connect(cycle[j], cycle[(j+1)%n]);
	}
	for (int i=0;i<N;i++) if (line[i] != i) connect(line[i], i);
	for (int i=0;i<N;i++) for (int j=i+1;j<N;j++){
		if (line[i] == line[j]){
			if (p[i][j] != 1) return 0;
		}
		else if (compo[i] == compo[j]){
			if (p[i][j] != 2) return 0;
		}else{
			if (p[i][j] != 0) return 0;
		}
	}
	build(answer);
	return 1;
}

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