#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;
vector<int> de;
void dfs(int v, int p = -1, int d = 0) {
de[v] = d;
tin[v] = curt;
curt++;
for (auto u : g[v]) {
if (u != p) {
dfs(u, v, d + 1);
}
}
tout[v] = curt;
curt++;
}
vector<int> label(int n, int k, vector<int> v, vector<int> u) {
curt = 0;
vector<int> res(n);
g.assign(n, {});
tin.assign(n, -1);
de.assign(n, 0);
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++) {
if (de[i] % 2 == 0) {
res[i] = tin[i];
} else {
res[i] = tout[i];
}
}
set<int> st;
for (auto el: res){
st.insert(el);
}
map<int, int> mp;
int ind = 0;
for (auto el : st) {
mp[el] = ind;
ind++;
}
for (int i = 0; i < n; i++) {
res[i] = mp[res[i]];
}
return res;
}
int find_next_station(int s, int t, vector<int> c) {
int p = -1;
bool is_tin = 1;
for (auto el : c) {
if (el < s) {
is_tin = 0;
}
}
if (s == 0) {
sort(c.rbegin(), c.rend());
int ind = 0;
while (ind < c.size() - 1 && c[ind + 1] >= t) {
ind++;
}
return c[ind];
}
if (is_tin) {
p = -1;
for (auto el : c) {
p = max(p, el);
}
if (t >= p || t <= s) {
return p;
}
sort(c.rbegin(), c.rend());
int ind = 1;
while (ind < c.size() - 1 && c[ind + 1] >= t) {
ind++;
}
if (ind < c.size() && c[ind] >= t)
return c[ind];
else
return p;
} else {
p = inf;
for (auto el : c) {
p = min(p, el);
}
if (t <= p || t >= s) {
return p;
}
sort(c.begin(), c.end());
int ind = 1;
while (ind < c.size() - 1 && c[ind + 1] <= t) {
ind++;
}
if (ind < c.size() && c[ind] <= t)
return c[ind];
else
return p;
}
}
/*
signed main() {
int n;
cin >> n;
vector<int> v(n - 1), u(n - 1);
for (int i = 0; i < n - 1; i++) {
cin >> v[i] >> u[i];
}
auto res = label(n,1000,v, u);
for (auto el : res ) {
cout << el << ' ';
}
cout << endl;
for (int i = 0; i < 1000; i++) {
int vq, uq;
cin >> vq >> uq;
int m;
cin >> m;
vector<int> c(m);
for (int j = 0; j < m; j++) {
cin >> c[j];
}
cout << find_next_station(vq, uq, c) << endl;
}
}
*/
