#include "stations.h"
#include <iostream>
#include <bits/stdc++.h>
#define fi first
#define se second
using namespace std;
int inf = 1e9 + 7;
vector<vector<int>> g;
vector<int> tin, tout;
int curt = 0;
int K = 5000;
void dfs(int v, int p = -1) {
tin[v] = curt;
curt++;
for (auto u : g[v]) {
if (u != p) {
dfs(u, v);
}
}
tout[v] = curt;
}
vector<int> label(int n, int k, vector<int> v, vector<int> u) {
vector<int> res(n);
g.assign(n, {});
tin.assign(n, -1);
tout.assign(n, -1);
for (int i = 0; i < n - 1; i++) {
g[v[i]].push_back(u[i]);
g[u[i]].push_back(v[i]);
}
dfs(0);
for (int i = 0; i < n; i++) {
res[i] = tin[i] * K + tout[i];
}
return res;
}
bool is_anc(int a, int b) {
int ai = a / K, ao = a % K, bi = b / K, bo = b % K;
return (ai <= bi && bo <= ao);
}
int find_next_station(int s, int t, vector<int> c) {
int p = -1;
for (auto el : c) {
if (is_anc(el, s)) {
p = el;
}
if (is_anc(el, t) && p != el) {
return el;
}
}
return p;
}
