#include "stations.h"
#include <vector>
#include <bits/stdc++.h>
using namespace std;
std::vector<int> label(int n, int k, std::vector<int> U, std::vector<int> V) {
vector<vector<int>> adj(n);
for(int i = 0; i < n - 1; i++) {
adj[U[i]].push_back(V[i]);
adj[V[i]].push_back(U[i]);
}
vector<int> tin(n), tout(n), d(n);
int timer = 0;
auto dfs = [&](auto &&self, int v, int p) -> void {
tin[v] = timer++;
for(auto to : adj[v]) {
if(to == p) continue;
d[to] = d[v] + 1;
self(self, to, v);
}
tout[v] = timer++;
};
dfs(dfs, 0, 0);
vector<int> lbl(n);
for(int i = 0; i < n; i++) {
lbl[i] = (d[i] & 1 ? tout[i] : tin[i]);
}
return lbl;
}
int find_next_station(int s, int t, std::vector<int> c) {
sort(c.begin(), c.end());
if(s < c[0]) { // tin
if(t < s || t > c.back()) return c.back();
return *lower_bound(c.begin(), c.end(), t);
} else { // tout
if(t < c[0] || t > s) return c[0];
return *(--upper_bound(c.begin(), c.end(), t));
}
}
