#include "stations.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> label(int n, int k, vector<int> u, vector<int> v) {
vector<int> deg(n);
vector<vector<int>> adj(n);
for (int i = 0; i < n - 1; i++)
deg[u[i]]++, deg[v[i]]++, adj[u[i]].push_back(v[i]), adj[v[i]].push_back(u[i]);;
vector<int> labels(n);
if (*max_element(deg.begin(), deg.end()) <= 2) {
int r = min_element(deg.begin(), deg.end()) - deg.begin(), p = -1;
labels[r] = 0;
for (int i = 1; i < n; i++) {
if (~p) adj[r].erase(find(adj[r].begin(), adj[r].end(), p));
tie(r, p) = make_pair(adj[r][0], r);
labels[r] = i;
}
} else {
iota(labels.begin(), labels.end(), 0);
}
return labels;
}
int find_next_station(int s, int t, vector<int> c) {
set<int> tmp; for (int x: c) tmp.insert(x+1);
int y = t+1;
if (tmp.count(y)) return y-1;
while (y > 0) {
y /= 2;
if (tmp.count(y))
return y-1;
}
return *min_element(c.begin(), c.end());
// return s < t ? *max_element(c.begin(), c.end()) : *min_element(c.begin(), c.end());
}
