Submission #600388

#	Time	Username	Problem	Language	Result	Execution time	Memory
600388		MilosMilutinovic	Village (BOI20_village)	C++14	100 / 100	98 ms	19024 KiB

Village

/**
 *    author:  wxhtzdy
 *    created: 20.07.2022 21:10:18
**/

/*
https://codeforces.com/contest/1387/submission/92450554
https://codeforces.com/contest/1387/submission/137586993
*/

#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);  
  int n;
  cin >> n;
  vector<vector<int>> g(n);
  for (int i = 0; i < n - 1; i++) {
    int u, v;
    cin >> u >> v;
    --u; --v;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  vector<pair<long long, vector<int>>> ans;
  {
    vector<int> p(n);
    iota(p.begin(), p.end(), 0);
    int cnt = 0;
    function<void(int, int)> Dfs = [&](int v, int pr) {
      for (int u : g[v]) {
        if (u != pr) {
          if (p[u] == u) {
            Dfs(u, v);
            if (p[u] == u) {
              cnt += 2;
              swap(p[v], p[u]);           
            }
          }
        }
      }
    };
    Dfs(0, 0);
    if (p[0] == 0) {
      cnt += 2;
      swap(p[0], p[g[0][0]]);
    }
    ans.emplace_back(cnt, p);  
  }
  {       
    int root;
    vector<int> sz(n); 
    function<void(int, int)> Dfs = [&](int v, int pr) {
      sz[v] = 1;
      int mx = 0;
      for (int u : g[v]) {
        if (u != pr) {
          Dfs(u, v);
          sz[v] += sz[u];
          mx = max(mx, sz[u]);
        }
      }
      if (mx * 2 < n && sz[v] * 2 >= n) {
        root = v;
      }
    };
    Dfs(0, 0);
    long long cnt = 0;
    vector<int> a;
    Dfs = [&](int v, int pr) {
      a.push_back(v);
      sz[v] = 1;
      for (int u : g[v]) {
        if (u != pr) {
          Dfs(u, v);
          sz[v] += sz[u];
          cnt += sz[u] * 2;
        }
      }      
    };
    Dfs(root, root);
    vector<int> b(n);
    for (int i = 0; i < n; i++) {
      b[a[i]] = a[(i + n / 2) % n]; 
    }
    ans.emplace_back(cnt, b);
  }
  cout << ans[0].first << " " << ans[1].first << '\n';
  for (int j = 0; j < 2; j++) {
    for (int i = 0; i < n; i++) {
      cout << ans[j].second[i] + 1 << " \n"[i == n - 1];
    }
  }  
  return 0;
}

• Subtask 1: 12 / 12
• Subtask 2: 38 / 38
• Subtask 3: 50 / 50