#include "stations.h"
#include <vector>
#include <bits/stdc++.h>
std::vector<int> label(int n, int k, std::vector<int> u, std::vector<int> v) {
std::vector<std::vector<int>> adj(n);
for (int i = 0; i < n - 1; i++) {
adj[v[i]].push_back(u[i]);
adj[u[i]].push_back(v[i]);
}
int timer = 0;
std::vector<int> st(n), ft(n), dep(n);
auto dfs = [&](auto self, int v, int f) -> void {
st[v] = timer++;
for (int u : adj[v]) {
if (u != f) {
dep[u] = dep[v] ^ 1;
self(self, u, v);
}
}
ft[v] = timer++;
};
dfs(dfs, 0, 0);
std::vector<int> all(n);
std::vector<int> id(n);
for (int i = 0; i < n; i++) {
id[i] = (dep[i] ? ft[i] : st[i]);
all[i] = id[i];
}
std::sort(all.begin(), all.end());
std::vector<int> res(2 * n + 1);
for (int i = 0; i < n; i++) {
res[all[i]] = i;
}
for (int i = 0; i < n; i++) {
id[i] = res[id[i]];
}
return id;
}
int find_next_station(int s, int t, std::vector<int> c) {
if (c.size() == 1) {
return c[0];
}
if (s >= *std::max_element(c.begin(), c.end())) {
for (int i = 1; i < c.size(); i++) {
int st = c[i];
int ft = (i + 1 == c.size() ? s - 1 : c[i + 1] - 1);
if (st <= t && t <= ft) {
return c[i];
}
}
return c[0];
} else {
for (int i = 0; i + 1 < c.size(); i++) {
int st = (i == 0 ? s + 1 : c[i - 1] + 1);
int ft = c[i];
if (st <= t && t <= ft) {
return c[i];
}
}
return c.back();
}
}
