#include "stations.h"
#include <bits/stdc++.h>
using namespace std;
int timer = -1;
void dfs(int node, int prev, int dpth, vector<vector<int>> &adj, vector<int> &tin, vector<int> &tout, vector<int> &deps) {
tin[node] = ++timer;
deps[node] = dpth;
for (auto &neighbour : adj[node]) {
if (neighbour == prev) continue;
dfs(neighbour, node, dpth + 1, adj, tin, tout, deps);
}
tout[node] = ++timer;
}
vector<int> label(int n, int k, vector<int> u, vector<int> v) {
timer = -1;
vector<int> ans(n), tin(n), tout(n), deps(n);
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]);
}
dfs(0, -1, 0, adj, tin, tout, deps);
vector<int> vals;
for (int i = 0; i < n; i++) {
ans[i] = (deps[i] % 2 ? tout[i] : tin[i]);
vals.push_back(ans[i]);
}
sort(vals.begin(), vals.end());
for (int i = 0; i < n; i++) {
ans[i] = lower_bound(vals.begin(), vals.end(), ans[i]) - vals.begin();
}
return ans;
}
bool cont(pair<int, int> &x, int y) {
return (y >= x.first && y <= x.second);
}
int find_next_station(int s, int t, std::vector<int> c) {
if (s > c[0]) {
// this is a tout
// c[0] is tin of par
for (int i = 1; i < (int)c.size() - 1; i++) {
pair<int, int> pr = {c[i], c[i + 1] - 1};
if (cont(pr, t)) return c[i];
}
// check last
pair<int, int> lst = {c.back(), s - 1};
if (cont(lst, t)) return c.back();
return c[0];
} else {
// this is a tin
// c.back is tout of par
//first
pair<int, int> fs = {s+1, c[0]};
if (cont(fs, t)) return c[0];
// rest
for (int i = 1; i < (int)c.size() - 1; i++) {
pair<int, int> pr = {c[i - 1] + 1, c[i]};
if (cont(pr, t)) return c[i];
}
return c.back();
}
}
