Distances

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

typedef long long ll;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef pair<ll,ll> pll;
typedef vector<bool> vb;
const ll oo = 0x3f3f3f3f3f3f3f3f;
const double eps = 1e-9;
#define sz(c) ll((c).size())
#define all(c) begin(c), end(c)
#define FOR(i,a,b) for (ll i = (a); i < (b); i++)
#define FORD(i,a,b) for (ll i = (b)-1; i >= (a); i--)
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define xx first
#define yy second
#define TR(X) ({ if(1) cerr << "TR: " << (#X) << " = " << (X) << endl; })

vl adj[111];

vl rec(ll i, ll p) {
	vl res = {i};
	for (ll j: adj[i]) if (j != p) {
		vl cur = rec(j,i);
		copy(rbegin(cur), rend(cur), back_inserter(res));
	}
	return res;
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	ll tc; cin >> tc;
	while (tc--) {
		ll n; cin >> n;
		FOR(i,1,n+1) adj[i].clear();
		
		FOR(i,1,n) {
			ll a, b;
			cin >> a >> b;
			adj[a].pb(b);
			adj[b].pb(a);
		}

		vl res = rec(1,0);
		for (ll a: res) cout << a << " ";
		cout << endl;
	}
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: ACCEPTED