Submission #420343

#	Time	Username	Problem	Language	Result	Execution time	Memory
420343		idk321	Connecting Supertrees (IOI20_supertrees)	C++17	56 / 100	327 ms	32020 KiB

supertrees

#include "supertrees.h"
#include <vector>

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

vector<vector<int>> p;
vector<vector<int>> groups;
vector<vector<int>> answer;
vector<int> isIn;
int n;
void dfs(int node, int cur, int par)
{
    isIn[node] = cur;
    groups[cur].push_back(node);
    if (par != -1)
    {
        answer[node][par] = 1;
        answer[par][node] = 1;
    }

    for (int i = 0; i < n; i++)
    {
        if (isIn[i] == -1 && p[node][i] == 1)
        {
            dfs(i, cur, node);
        }
    }
}

int construct(std::vector<std::vector<int>> P) {
    p = P;
	n = p.size();
    for (int i = 0; i < n; i++)
    {
        for (int j = i; j < n; j++)
        {
            if (p[i][j] >= 3) return 0;
        }
    }



    isIn.resize(n, -1);
    answer.resize(n, vector<int>(n));

    int cur = 0;
    for (int i = 0; i < n; i++)
    {
        if (isIn[i] == -1)
        {
            groups.push_back(vector<int>());
            dfs(i, cur, -1);
            cur++;
        }
    }

    for (auto g : groups)
    {
        for (int i = 0; i < g.size(); i++)
        {
            for (int j = i + 1; j < g.size(); j++)
            {
                if (p[g[i]][g[j]] != 1) return 0;
            }
        }
    }


    vector<vector<int>> relation(n, vector<int>(n, -1));
    for (int i = 0; i < n; i++)
    {
        for (int j = i + 1; j < n; j++)
        {
            if (isIn[i] != isIn[j])
            {
                if (relation[isIn[i]][isIn[j]] == -1)
                {
                    relation[isIn[i]][isIn[j]] = p[i][j];
                    relation[isIn[j]][isIn[i]] = p[i][j];
                } else if (relation[isIn[i]][isIn[j]] != p[i][j]) return 0;
            }
        }
    }

    for (int i = 0; i < groups.size(); i++)
    {
        int next = i + 1;
        while (next != i)
        {
            next %= groups.size();
            if (relation[i][next] == 2)
            {
                answer[groups[i].front()][groups[next].front()] = 1;
                answer[groups[next].front()][groups[i].front()] = 1;
                break;
            }
            next++;
            next %= groups.size();
        }
    }



	build(answer);

	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:60:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   60 |         for (int i = 0; i < g.size(); i++)
      |                         ~~^~~~~~~~~~
supertrees.cpp:62:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |             for (int j = i + 1; j < g.size(); j++)
      |                                 ~~^~~~~~~~~~
supertrees.cpp:86:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   86 |     for (int i = 0; i < groups.size(); i++)
      |                     ~~^~~~~~~~~~~~~~~

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