#include "stations.h"
#include <bits/stdc++.h>
#define rep2(i,a,b) for(int i = (a); i <= (b); i++)
#define pb push_back
using namespace std;
vector<int> graf[1001];
int pre[1001];
int akt_pre = 0;
void dfs(int v, int pop, int dist)
{
if(dist % 2 == 0) pre[v] = akt_pre;
akt_pre++;
for(auto& it: graf[v])
{
if(it != pop) dfs(it,v,dist+1);
}
if(dist % 2 == 1) pre[v] = akt_pre;
akt_pre++;
}
vector<int> label(int n, int k, vector<int> u, vector<int> v)
{
rep2(i,0,n-1) graf[i].clear();
rep2(i,0,n-2)
{
graf[u[i]].pb(v[i]);
graf[v[i]].pb(u[i]);
}
akt_pre = 0;
dfs(0,0,0);
vector<pair<int,int>> labels;
rep2(i,0,n-1) labels.pb({pre[i],i});
sort(labels.begin(),labels.end());
vector<int> ans(n);
int akt_poz = 0;
for(auto& it: labels)
{
ans[it.second] = akt_poz;
akt_poz++;
}
//for(auto it: ans)
//{
// cout << it << " ";
//}
//cout << " ans\n";
return ans;
}
int find_next_station(int s, int t, vector<int> post)
{
// post
int n = (int)post.size();
vector<int> nums(n);
rep2(i,0,n-1) nums[i] = post[i];
vector<int> pre(n);
int root;
if(s > post[0])
{
root = 0;
swap(pre,post);
int pop = s;
for(int i = n-1; i >= 1; i--)
{
post[i] = pop-1;
pop = pre[i];
}
}
else //pre
{
root = n-1;
int pop = s;
for(int i = 0; i < n-1; i++)
{
pre[i] = pop+1;
pop = post[i];
}
}
for(int i = 0; i < n; i++)
{
if(i == root) continue;
//cout << nums[i] << " " << pre[i] << " " << post[i] << " pre/post\n";
if(t >= pre[i] && t <= post[i])
{
//cout << nums[i] << " return\n";
return nums[i];
}
}
//cout << nums[root] << " " << root << " return\n";
return nums[root];
}
