Distances

#include <bits/stdc++.h>

using namespace std;

int n;
vector<int> g[105];
int dad[105];

vector<int> dfs(int u) {
    vector<int> ret;
    ret.push_back(u);
    for (auto v: g[u]) {
        if (v == dad[u]) continue;
        dad[v] = u;
        vector<int> add = dfs(v);
        reverse(add.begin(), add.end());
        for (auto x: add) ret.push_back(x);
    }
    return ret;
}

int main(void) {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int ntest;
    cin >> ntest;
    while (ntest--) {
        cin >> n;
        for (int i = 1; i <= n; ++i) g[i].clear();
        for (int i = 1; i < n; ++i) {
            int u, v;
            cin >> u >> v;
            g[u].push_back(v);
            g[v].push_back(u);
        }
        memset(dad, 0, sizeof dad);

        vector<int> ans = dfs(1);
        for (auto x: ans) cout << x << ' ';
        cout << endl;
    }
    return 0;
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: ACCEPTED