#include "meetings.h"
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using vi = vector<int>;
using vl = vector<ll>;
using vb = vector<bool>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using str = string;
#define all(a) a.begin(), a.end()
#define print(a) for (auto elem:a) cout<<elem<<' '; cout<<'\n'
#define segprep(b) resize(1<<((int)ceil(log2(b.size()))+1))
#define FOR(a) for (int _ = 0; _ < a; _++)
const int SEED = 1;
int randint(const int l, const int r){
int res = rand()%(r-l)+l;
assert(l <= res && res < r);
return res;
}
int n;
vector<vi> graph;
void solve_set(vi verts){
// print(verts);
if (verts.size() == 1) return;
if (verts.size() == 2){
int first = verts.front(), second = verts.back();
if (first > second) swap(first, second);
Bridge(first, second);
graph.at(first).push_back(second);
graph.at(second).push_back(first);
return;
}
int root_ind = randint(0, (int)verts.size());
int second_ind = randint(0, (int)verts.size()-1);
if (second_ind >= root_ind) second_ind++;
int root = verts.at(root_ind), second = verts.at(second_ind);
vi subtr = {second};
vi left_nodes = {root};
vb in_path_to_second(n, false);
queue<int> to_chk;
for (auto &i:verts){
if (i != root && i != second){
int ans = Query(root, second, i);
if (ans == root){
left_nodes.push_back(i);
continue;
}
subtr.push_back(i);
if (ans == i){
in_path_to_second.at(i) = true;;
}
}
}
solve_set(subtr);
solve_set(left_nodes);
// znalezc polaczenie
int vert = second, parent = second;
bool moved;
do{
moved = false;
for (const auto &son:graph.at(vert)){
if (son != parent && in_path_to_second.at(son)){
parent = vert;
vert = son;
moved = true;
}
}
} while(moved);
if (vert > root) swap(vert, root);
Bridge(vert, root);
graph.at(vert).push_back(root);
graph.at(root).push_back(vert);
}
void Solve(int N){
n = N;
srand(SEED);
graph.resize(n);
vi nodes(n);
for (int i = 0; i < n; i++) nodes.at(i) = i;
solve_set(nodes);
}
