Submission #792733

#	Time	Username	Problem	Language	Result	Execution time	Memory
792733		mousebeaver	Connecting Supertrees (IOI20_supertrees)	C++14	0 / 100	177 ms	22016 KiB

supertrees

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

int construct(vector<vector<int>> p) 
{
	int n = p.size();
	vector<bool> used(n, false);
	vector<vector<int>> adjmatrix(n, vector<int> (n, 0));

	for(int i = 0; i < n; i++)
	{
		if(used[i]) continue;

		//Collect the component:
		vector<int> component(0);
		for(int j = 0; j < n; j++)
		{
			if(p[i][j] == 3)
			{
				return 0;
			}
			if(p[i][j])
			{
				component.push_back(j);
				used[j] = true;
			}
		}

		for(int j : component)
		{
			if(count(p[j].begin(), p[j].end(), 0) != n- (int) component.size())
			{
				return 0;
			}
			for(int k : component)
			{
				if(p[i][j] == 0)
				{
					return 0;
				}
			}
		}

		//Build the forest:
		vector<bool> tree(component.size(), false);
		vector<vector<int>> forest(0);
		for(int j = 0; j < (int) component.size(); j++)
		{
			if(tree[j]) continue;
			vector<int> t(0);
			for(int k = 0; k < (int) component.size(); k++)
			{
				if(p[j][k] == 1)
				{
					t.push_back(k);
					tree[k] = true;
				}
			}
			assert(t.size() == 1);
			forest.push_back(t);

			//Build the tree:
			for(int k = 0; k < (int) t.size()-1; k++)
			{
				adjmatrix[t[k]][t[k+1]] = 1;
				adjmatrix[t[k+1]][t[k]] = 1;
			}
		}

		//Test the partitioning:
		for(int j = 0; j < (int) forest.size(); j++)
		{
			for(int a : forest[j])
			{
				for(int k = 0; k < (int) forest.size(); k++)
				{
					for(int b : forest[k])
					{
						if((k == j && p[a][b] != 1) ||
							(k != j && p[a][b] != 2))
							{
								return 0;
							}
					}
				}
			}
		}

		//Connect the trees:
		if(forest.size() == 2)
		{
			return 0;
		}
		if(forest.size() > 2)
		{
			for(int j = 0; j < (int) forest.size()-1; j++)
			{
				adjmatrix[forest[j][0]][forest[j+1][0]] = 1;
				adjmatrix[forest[j+1][0]][forest[j][0]] = 1;
			}
			adjmatrix[forest[0][0]][forest[forest.size()-1][0]] = 1;
			adjmatrix[forest[forest.size()-1][0]][forest[0][0]] = 1;
		}
	}

	build(adjmatrix);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:36:12: warning: unused variable 'k' [-Wunused-variable]
   36 |    for(int k : component)
      |            ^

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