Submission #603554

#	Time	Username	Problem	Language	Result	Execution time	Memory
603554		CyberCow	Connecting Supertrees (IOI20_supertrees)	C++17	11 / 100	218 ms	30220 KiB

supertrees

#include "supertrees.h"
#include <vector>
#include <queue>
#include <unordered_set>
using namespace std;

int construct(vector<vector<int>> p) {
	int n = p.size();
	vector<vector<int>> ans(n);
	vector<int> a(n);
	vector<int> g[1005];
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < n; j++)
		{
			ans[i].push_back(0);
			if (p[i][j])
			{
				g[i].push_back(j);
				g[j].push_back(i);
			}
		}
	}
	int st1 = 0, st2 = 0, st0 = 0;
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < p[i].size(); j++)
		{
			if (p[i][j] == 1)
				st1 = 1;
			else if (p[i][j] == 2)
				st2 = 1;
			else
				st0 = 1;
		}
	}
	if (st1 == 1 && st2 == 0 && st0 == 0)
	{
		for (int i = 1; i < n; i++)
		{
			ans[0][i] = 1;
		}
		for (int i = 1; i < n; i++)
		{
			ans[i][0] = 1;
		}
	}
	else if ((st0 == 1 || st1 == 1) && st2 == 0)
	{
		queue<int> q;
		for (int i = 0; i < n; i++)
		{
			if (a[i] == 0)
			{
				vector<int> va;
				q.push(i);
				while (!q.empty())
				{
					int x = q.front();
					va.push_back(x);
					a[x] = 1;
					q.pop();
					for (int j = 0; j < g[x].size(); j++)
					{
						if (a[g[x][j]] == 0)
						{
							q.push(g[x][j]);
							a[g[x][j]] = 1;
						}
					}
				}
				for (int j = 0; j < va.size() - 1; j++)
				{
					ans[va[j]][va[j + 1]] = 1;
					ans[va[j + 1]][va[j]] = 1;
				}
			}
		}
		for (int i = 0; i < n; i++)
		{
			for (int j = 0; j < n; j++)
			{
				if (p[i][j] == 0 && ans[i][j] != 0)
					return 0;
			}
		}
	}
	build(ans);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:27:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |   for (int j = 0; j < p[i].size(); j++)
      |                   ~~^~~~~~~~~~~~~
supertrees.cpp:63:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |      for (int j = 0; j < g[x].size(); j++)
      |                      ~~^~~~~~~~~~~~~
supertrees.cpp:72:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |     for (int j = 0; j < va.size() - 1; j++)
      |                     ~~^~~~~~~~~~~~~~~

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