Etäisyydet

input/code.cpp: In function 'void search(int)':
input/code.cpp:82:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if (answer.size() == n) {
       ~~~~~~~~~~~~~~^~~~

#include <iostream>
#include <algorithm>
#include <vector>
 
typedef long long ll;
using namespace std;
 
int n;
 
vector<vector<int>> vieruslista;
 
ll d[101][101];
ll v[101][101];
 
int z[101];
 
void calculateDistances() {
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= n; j++) {
      if (i==j) d[i][j] = 0;
      else if (v[i][j]) d[i][j] = v[i][j];
      else d[i][j] = 1e18;
    }
  }
 
  for (int k = 1; k <= n; k++) {
    for (int i = 1; i <= n; i++) {
      for (int j = 1; j <= n; j++) {
        d[i][j] = min(d[i][j], d[i][k]+d[k][j]);
      }
    }
  }
 
  vieruslista.clear();
  vieruslista.resize(n+1);
  for (int i = 1; i <= n; i++) {
    for (int j = i+1; j <= n; j++) {
      if (d[i][j] <= 3) {
        vieruslista[i].push_back(j);
        vieruslista[j].push_back(i);
      }
    }
  }
}
 
void readValues() {
  cin >> n;
 
  for (int i = 0; i < 101; i++) z[i] = 0;
 
  for (int i = 0; i <= n; i++) {
    for (int j = 0; j <= n; j++) {
      v[i][j] = 0;
      v[j][i] = 0;
      d[i][j] = 0;
      d[j][i] = 0;
    }
  }
 
  for (int i = 0; i < n-1; i++) {
    int a, b; cin>>a>>b;
    v[a][b] = 1;
    v[b][a] = 1;
  }
}
 
 
vector<int> answer;
bool found = false;
 
void search(int s) {
  //cout << "Solmu " << s << "\n";
  if (found) return;
  answer.push_back(s);
  z[s] = 1;
 
  //cout << "here " << s << "\n";
  //for (int x : answer) cout << x << " ";
  //cout << "\n"; 
  
 
  if (answer.size() == n) {
    found = true;
    for (int x : answer) cout << x << " ";
    cout << "\n";
    //cout << "found";
    return;
  }
 
  for (int u : vieruslista[s]) {
    //cout << "Solmu " << u << "\n";
    if (z[u]) continue;
    //cout << "Solmujen etäisyys " << d[s][u] << "\n";
      //cout << "Etsitään " << u << "\n";
     search(u);
    
  }
 
  z[s] = 0;
  answer.pop_back();
}
 
int main() {
  //ios_base::sync_with_stdio(0);
  //cin.tie(0);
 
  int t; cin>>t;
 
  for (int i = 0; i < t; i++) {
    readValues();
    calculateDistances();
    answer.clear();
    
    //while (true) {
     // int a, b; cin >> a >> b;
    //  cout << "Etäisyys " << d[a][b] << "\n";
    //}
 
 
    for (int i = n; i > 0; i--) {
      found = false;
      search(i);
      if (found) break;
    }
  }
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: TIME LIMIT EXCEEDED