Distances

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

void dfs(int u, int p, vector<int> &dist) {
  for (auto& v : g[u]) {
    if (v != p) {
      dist[v] = dist[u] + 1;
      dfs(v, u, dist);
    }
  }
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);  
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    g.assign(n + 1, vector<int>());
    for (int i = 0; i < n - 1; i++) {
      int u, v;
      cin >> u >> v;
      g[u].push_back(v);
      g[v].push_back(u);
    }
    vector< vector<int> > dist(n + 1, vector<int>(n + 1, 0));
    for (int i = 1; i <= n; i++) dfs(i, -1, dist[i]);
    vector<int> perm(n);
    iota(perm.begin(), perm.end(), 1);
    do {
      int mx = 0;
      for (int i = 0; i < n - 1; i++) mx = max(mx, dist[perm[i]][perm[i + 1]]);
      if (mx <= 3) {
        break;
      }
    } while (next_permutation(perm.begin(), perm.end()));
    for (auto& x : perm) cout << x << ' ';
    cout << '\n';
  }
  return 0;  
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: TIME LIMIT EXCEEDED