Submission #300236

#	Time	Username	Problem	Language	Result	Execution time	Memory
300236		madlogic	Connecting Supertrees (IOI20_supertrees)	C++17	0 / 100	1 ms	384 KiB

supertrees

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

using namespace std;

int construct(std::vector<std::vector<int>> p) {
  int n = p.size();
  vector<vector<int>> adj(n);
  bool two = false;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) if (p[i][j]) {
      two |= p[i][j] == 2;
      adj[i].push_back(j);
      adj[j].push_back(i);
    }
  }
  vector<int> cc;
  vector<bool> vis(n);
  function<void(int)> dfs = [&](int u) {
    vis[u] = true;
    cc.push_back(u);
    for (int to : adj[u]) if (!vis[to]) {
      dfs(to);
    }
  };
  vector<vector<int>> answer(n, vector<int>(n));
  for (int i = 0; i < n; i++) {
    if (!vis[i]) {
      dfs(i);
      int m = cc.size();
      int edges = 0;
      for (int p : cc)
        edges += adj[p].size();
      edges /= 2;
      if (m == 1) {
        answer[cc[0]][cc[0]] = 1;
        continue;
      }
      if (m == 2 && two)
        return 0;
      // if (edges >= m) 
      //   return 0;
      for (int j = 0; j < m - 1; j++)
        answer[cc[j]][cc[j + 1]] = answer[cc[j + 1]][cc[j]] = 1;
      if (two)
        answer[cc[0]][cc[m - 1]] = answer[cc[m - 1]][cc[0]] = 1;
      for (int j = 0; j < m; j++) {
        for (int k = 0; k < m; k++) {
          if (p[cc[j]][cc[k]] == 0)
            return 0;
        }
      }
      cc.clear();
    }
  }
  build(answer);
  return 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