Submission #880450

#	Time	Username	Problem	Language	Result	Execution time	Memory
880450		AkibAzmain	Connecting Supertrees (IOI20_supertrees)	C++17	0 / 100	1 ms	348 KiB

supertrees

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

int construct(std::vector<std::vector<int>> p) {
  int n = p.size();
  std::vector<std::vector<int>> ans (n, vector < int > (n));
  vector < pair < int, int > > dsu (n);
  for (int i = 0; i < n; ++i) dsu[i].first = -1, dsu[i].second = 1;
  for (int i = 0; i < n; ++i)
    {
      if (p[i][i] != 1) return 0;
      for (int j = i + 1; j < n; ++j)
        {
          if (p[j][i] != p[i][j]) return 0;
          if (p[i][j] == 2)
            {
              int ci = i, cj = j;
              while (dsu[ci].first != -1) ci = dsu[ci].first;
              while (dsu[cj].first != -1) cj = dsu[cj].first;
              if (ci != cj)
                {
                  if (dsu[ci].second < dsu[cj].second) swap (ci, cj);
                  dsu[cj].first = ci;
                  dsu[ci].second += dsu[cj].second;
                }
            }
        }
    }
  for (int i = 0; i < n; ++i)
    for (int j = i + 1; j < n; ++j)
      if (p[i][j] == 0)
        {
          if (p[j][i] != p[i][j]) return 0;
          int ci = i, cj = j;
          while (dsu[ci].first != -1) ci = dsu[ci].first;
          while (dsu[cj].first != -1) cj = dsu[cj].first;
          if (ci == cj) return 0;
        }
  map < int, vector < int > > s;
  for (int i = 0; i < n; ++i)
    {
      int ci = i;
      while (dsu[ci].first != -1) ci = dsu[ci].first;
      s[ci].push_back (i);
    }
  for (auto &[y, ss] : s)
    {
      for (int i = 1; i < ss.size (); ++i) ans[ss[i]][ss[i - 1]] = ans[ss[i - 1]][ss[i]] = 1;
      if (ss.size () > 1) ans[ss.front ()][ss.back ()] = ans[ss.back ()][ss.front ()] = 1;
    }
  build (ans);
  return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:50:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |       for (int i = 1; i < ss.size (); ++i) ans[ss[i]][ss[i - 1]] = ans[ss[i - 1]][ss[i]] = 1;
      |                       ~~^~~~~~~~~~~~

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