#include "parks.h"
#include <bits/stdc++.h>
using namespace std;
int construct_roads(vector<int> x, vector<int> y) {
if (x.size() == 1) {
build({}, {}, {}, {});
return 1;
}
int n = x.size();
vector<pair<int, int>> p2, p4;
for (int i = 0; i < n; i++) {
if (x[i] == 2) {
p2.emplace_back(y[i], i);
} else if (x[i] == 4) {
p4.emplace_back(y[i], i);
}
}
sort(p2.begin(), p2.end());
sort(p4.begin(), p4.end());
vector<int> u, v, a, b;
for (int j = 1; j < (int) p2.size(); j++) {
int i = p2[j].second;
int k = p2[j - 1].second;
if (y[i] - y[k] > 2) {
continue;
}
u.push_back(k);
v.push_back(i);
a.push_back(1);
b.push_back(y[i] - 1);
}
for (int j = 1; j < (int) p4.size(); j++) {
int i = p4[j].second;
int k = p4[j - 1].second;
if (y[i] - y[k] > 2) {
continue;
}
u.push_back(k);
v.push_back(i);
a.push_back(5);
b.push_back(y[i] - 1);
}
for (int i = 0, j = 0; i < (int) p2.size(); i++) {
while (j < (int) p4.size() && p4[j].first < p2[i].first) {
j++;
}
if (j >= (int) p4.size()) {
break;
}
if (p2[i].first == p4[j].first) {
int ii = p2[i].second;
int jj = p4[j].second;
u.push_back(ii);
v.push_back(jj);
a.push_back(3);
b.push_back(y[ii] - 1);
}
}
auto dist = [&](int i, int j) {
return (x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]);
};
vector<vector<int>> g(n);
for (int i = 0; i < (int) u.size(); i++) {
if (dist(u[i], v[i]) > 4) {
return 0;
}
g[u[i]].push_back(v[i]);
g[v[i]].push_back(u[i]);
}
vector<int> vis(n, 0);
function<void(int)> dfs = [&](int uu) {
if (vis[uu]) {
return;
}
vis[uu] = 1;
for (int vv : g[uu]) {
dfs(vv);
}
};
dfs(0);
if (accumulate(vis.begin(), vis.end(), 0) == n) {
build(u, v, a, b);
return 1;
}
return 0;
}
