#include <bits/stdc++.h>
#include "stations.h"
using namespace std;
const int MAXN = 100005;
vector<int> adj[MAXN];
int tin[MAXN], tout[MAXN];
int timer;
void dfs_label(int u, int p) {
tin[u] = timer++;
for (int v : adj[u]) {
if (v == p) continue;
dfs_label(v, u);
}
tout[u] = timer - 1;
}
vector<int> label(int n, int k, vector<int> u, vector<int> v) {
for (int i = 0; i < n; i++) adj[i].clear();
timer = 0;
for (int i = 0; i < (int)u.size(); i++) {
adj[u[i]].push_back(v[i]);
adj[v[i]].push_back(u[i]);
}
dfs_label(0, -1);
vector<int> labels(n);
for (int i = 0; i < n; i++) {
labels[i] = tin[i];
}
return labels;
}
int find_next_station(int s, int t, vector<int> c) {
for (int v : c) {
if (tin[v] <= tin[t] && tin[t] <= tout[v]) {
return v;
}
}
return -1;
}
