Submission #1087750

#	Time	Username	Problem	Language	Result	Execution time	Memory
1087750		T0p_	Connecting Supertrees (IOI20_supertrees)	C++14	100 / 100	141 ms	24404 KiB

supertrees

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

using namespace std;

const int N = 1000;

bool is_add[N];
int tree_parent[N], circular_parent[N];

int find_tree_parent(int u) {
	return tree_parent[u] = (u == tree_parent[u])
		? u
		: find_tree_parent(tree_parent[u]); 
}

int find_circular_parent(int u) {
	return circular_parent[u] = (u == circular_parent[u])
		? u
		: find_circular_parent(circular_parent[u]); 
}

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

	for (int i=0 ; i<n ; i++) {
		for (int j=0 ; j<n ; j++) {
			if (p[i][j] == 3) {
				return 0;
			}
		}
	}

	for (int i=0 ; i<n ; i++) {
		tree_parent[i] = i;
		circular_parent[i] = i;
	}

	for (int i=0 ; i<n ; i++) {
		for (int j=i+1 ; j<n ; j++) {
			if (p[i][j] == 1) {
				int ii = find_tree_parent(i);
				int jj = find_tree_parent(j);

				if (ii != jj) {
					tree_parent[ii] = jj;
					ans[i][j] = ans[j][i] = 1;
				}
			}
		}
	}

	for (int i=0 ; i<n ; i++) {
		for (int j=i+1 ; j<n ; j++) {
			int ii = find_tree_parent(i);
			int jj = find_tree_parent(j);

			if (p[i][j] != 1 && ii == jj) {
				return 0;
			}
		}
	}

	for (int i=0 ; i<n ; i++) {
		for (int j=i+1 ; j<n ; j++) {
			if (p[i][j] == 2) {
				int ii = find_circular_parent(find_tree_parent(i));
				int jj = find_circular_parent(find_tree_parent(j));

				circular_parent[ii] = jj;
			}
		}
	}

	vector<int> group[N];
	for (int i=0 ; i<n ; i++) {
		int tree_i = find_tree_parent(i);

		if (is_add[tree_i]) continue;
		is_add[tree_i] = true;

		int circular_i = find_circular_parent(tree_i);
		group[circular_i].push_back(tree_i);
	}

	for (int i=0 ; i<N ; i++) {

		int sz = group[i].size();

		if (sz <= 1) {
			continue;
		}
		else if (sz == 2) {
			return 0;
		}
		else {
			for (int j=0 ; j<sz-1 ; j++) {
				ans[group[i][j]][group[i][j+1]] = ans[group[i][j+1]][group[i][j]] = 1;
			}
			ans[group[i][0]][group[i][sz-1]] = ans[group[i][sz-1]][group[i][0]] = 1;
		}
	}

	for (int i=0 ; i<n ; i++) {
		for (int j=i+1 ; j<n ; j++) {
			int tree_i = find_tree_parent(i);
			int tree_j = find_tree_parent(j);
			int circular_i = find_circular_parent(tree_i);
			int circular_j = find_circular_parent(tree_j);

			if (p[i][j] != 2 && circular_i == circular_j && tree_i != tree_j) {
				return 0;
			}
		}
	}

	build(ans);
	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