#include "parks.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> adj[200005], X, Y, U, V, A, B;
vector<pair<int, int> > edge;
map<pair<int, int>, bool> mp;
map<pair<int, int>, int> p;
bool visited[200005];
queue<int> q;
bool cmp(pair<int, int> u, pair<int, int> v)
{
if (X[u.first]!=X[v.first] || X[u.second]!=X[v.second])
return (X[u.first]<X[v.first] || X[u.second]<X[v.second]);
return Y[u.first]<Y[v.first];
}
int construct_roads(vector<int> x, vector<int> y)
{
int N=x.size();
for (int i=0; i<N; i++)
{
X.push_back(x[i]);
Y.push_back(y[i]);
p[{X[i], Y[i]}]=i+1;
}
for (auto itr=p.begin(); itr!=p.end(); itr++)
{
int ind=itr->second-1;
if (p.count({X[ind]-2, Y[ind]}))
edge.push_back({p[{X[ind]-2, Y[ind]}]-1, ind});
if (p.count({X[ind], Y[ind]-2}))
edge.push_back({p[{X[ind], Y[ind]-2}]-1, ind});
}
sort(edge.begin(), edge.end(), cmp);
for (int i=0; i<edge.size(); i++)
{
int u=edge[i].first, v=edge[i].second;
adj[u].push_back(v);
adj[v].push_back(u);
U.push_back(u);
V.push_back(v);
if (X[u]==X[v])
{
if (!mp[{X[u]-1, Y[u]+1}])
{
A.push_back(X[u]-1);
B.push_back(Y[u]+1);
mp[{X[u]-1, Y[u]+1}]=1;
}
else if (!mp[{X[u]+1, Y[u]+1}])
{
A.push_back(X[u]+1);
B.push_back(Y[u]+1);
mp[{X[u]+1, Y[u]+1}]=1;
}
else
return 0;
}
else
{
if (!mp[{X[u]+1, Y[u]-1}])
{
A.push_back(X[u]+1);
B.push_back(Y[u]-1);
mp[{X[u]+1, Y[u]-1}]=1;
}
else if (!mp[{X[u]+1, Y[u]+1}])
{
A.push_back(X[u]+1);
B.push_back(Y[u]+1);
mp[{X[u]+1, Y[u]+1}]=1;
}
else
return 0;
}
}
q.push(0);
visited[0]=1;
while (!q.empty())
{
int u=q.front();
q.pop();
for (int v:adj[u])
{
if (!visited[v])
{
q.push(v);
visited[v]=1;
}
}
}
for (int i=0; i<N; i++)
if (!visited[i])
return 0;
build(U, V, A, B);
return 1;
}
