#include"stations.h"
#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
#define vi vector<int>
#define vvi vector<vi>
vi M1, M2;
vvi Adj;
int k = 0;
void dfs(int p) {
M1[p] = k;
for (int i : Adj[p]) {
if (M1[i] != -1) continue;
dfs(i);
}
M2[M1[p]] = k;
}
vi label(int n, int k, vi u, vi v) {
Adj.resize(n);
for (int i = 0; i < n-1; i++) {
Adj[u[i]].push_back(v[i]);
Adj[v[i]].push_back(u[i]);
}
M1.resize(n, -1);
M2.resize(n, -1);
dfs(0);
return M1;
}
int find_next_station(int s, int t, vi c) {
if (s > t) return c[0];
if (M2[s] > t) return c[0];
for (int i = c.size()-1; i > -1; i--) {
if (c[i] < t) return c[i];
}
return 0;
}
