Distances

#include <bits/stdc++.h>
using namespace std;
 
const int MAXN=1e2+5;
 
int T, N;
vector <int> V[MAXN];
 
void dfs(int par,int now,bool last) {
	if (!last) {
		cout<<now<<' ';
	}
	for (int next : V[now]) {
		if (next==par) continue;
		dfs(now,next,!last);
	}
	if (last) {
		cout<<now;
		if (par==0) {
			cout<<'\n';
		}
		else {
			cout<<' ';
		}
	}
}
 
int main() {
	cin>>T;
	for (int i=1;i<=T;i++) {
		cin>>N;
		for (int j=1;j<N;j++) {
			int x, y;
			cin>>x>>y;
			V[x].push_back(y);
			V[y].push_back(x);
		}
		dfs(0,1,1);
		for (int j=1;j<=N;j++) {
			V[j].clear();
		}
	}
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: ACCEPTED