#include "parks.h"
#include<bits/stdc++.h>
using namespace std;
vector<vector<int>> adj;
vector<bool> vis;
void dfs(int i)
{
if(vis[i])
return;
vis[i] = 1;
for(auto j : adj[i])
{
dfs(j);
}
}
void add_edge(int u , int v)
{
adj[u].push_back(v);
adj[v].push_back(u);
}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int construct_roads(std::vector<int> x, std::vector<int> y) {
int n= (int)x.size();
adj.assign(n , {});
vis.assign(n , 0);
vector<int> u , v , a , b;
map<pair<int, int> , int> idx;
set<pair<int ,int>> taken;
for(int i = 0 ; i <n ; i++)
{
idx[{x[i] , y[i]}] = i;
}
vector<pair<int ,int>> vv;
for(int i = 0 ; i < n ; i++)
vv.push_back({x[i] , y[i]});
int cnt = 1;
while(cnt--)
{
u.clear();
v.clear();
a.clear();
b.clear();
taken.clear();
adj.assign(n , {});
vis.assign(n ,0);
shuffle(vv.begin() , vv.end() , rng);
for(int i = 0 ; i < n ;i++)
{
x[i] = vv[i].first , y[i] = vv[i].second;
}
bool acc = 1;
for(int i = 0 ; i < n ;i++)
{
if(idx.count({x[i] + 2 , y[i]}))
{
if(!taken.count({x[i] + 1 , y[i] - 1}))
{
u.push_back(idx[{x[i] , y[i]}]);
v.push_back(idx[{x[i] + 2 , y[i]}]);
a.push_back(x[i] + 1);
b.push_back(y[i] - 1);
taken.insert({x[i] + 1 , y[i] - 1});
}
else if(!taken.count({x[i] + 1 , y[i] + 1}))
{
u.push_back(idx[{x[i] , y[i]}]);
v.push_back(idx[{x[i] + 2 , y[i]}]);
a.push_back(x[i] + 1);
b.push_back(y[i] + 1);
taken.insert({x[i] + 1 , y[i] + 1});
}
}
if(idx.count({x[i] , y[i] + 2}))
{
if(!taken.count({x[i] - 1 , y[i] + 1}))
{
u.push_back(idx[{x[i] , y[i]}]);
v.push_back(idx[{x[i] , y[i] + 2}]);
b.push_back(y[i] + 1);
a.push_back(x[i] - 1);
taken.insert({x[i] - 1 , y[i] +1});
}
else if(!taken.count({x[i] + 1 , y[i] + 1}))
{
u.push_back(idx[{x[i] , y[i]}]);
v.push_back(idx[{x[i] , y[i] + 2}]);
b.push_back(y[i] + 1);
a.push_back(x[i] + 1);
taken.insert({x[i] + 1 , y[i] +1});
}
}
}
for(int i = 0 ; i < (int)u.size() ; i++)
{
add_edge(u[i] , v[i]);
}
dfs(0);
for(int i = 0 ; i < n ; i++)
{
if(!vis[i])
{
acc = 0;
break;
}
}
if(!acc)
continue;
build(u , v , a , b);
return 1;
}
return 0;
}
