Distances

#include <bits/stdc++.h>
#define X first
#define Y second
#define sz(a) (int)a.size()
#define pb push_back
#define int long long

using namespace std;
typedef long long ll;

void solve();

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int t = 1;
    cin >> t;
    while (t--)
        solve();
    return 0;
}

vector <int> g[110];

bitset <110> b;

int ans = -1, dd = 0;

vector <int> pans;

void dfs(int v, int d, int pr) {
    if (d == 4)
        return;
    if (!b[v]) {
        if (dd < d) {
            dd = d;
            ans = v;
        }
    }
    for (auto u : g[v]) {
        if (pr != u) {
            dfs(u, d + 1, v);
        }
    }
}

void solve() {
    b = 0;
    int n, x, y;
    cin >> n;
    for (int i = 0; i < n; ++i) {
        g[i].clear();
    }
    pans.clear();
    for (int i = 0; i < n - 1; ++i) {
        cin >> x >> y;
        x--;
        y--;
        g[x].pb(y);
        g[y].pb(x);
    }
    for (int i = 0; i < n; ++i) {
        if (sz(g[i]) == 1) {
            b[i] = 1;
            pans.pb(i);
        }
    }
    while (sz(pans) != n) {
        ans = -1, dd = 0;
        dfs(pans.back() - 1, 0, -1);
        b[ans] = 1;
        pans.pb(ans + 1);
    }
    for (auto i : pans) {
        cout << i << " ";
    }
    cout << '\n';
    return;
}

Test 1

Group: 1, 2

Verdict: WRONG ANSWER

Test 2

Group: 2

Verdict: RUNTIME ERROR