#include <bits/stdc++.h>
#include "parks.h"
using namespace std;
#define all(x) (x).begin(), (x).end()
const int mxn = 2e5 + 100;
int ldr[mxn], rnk[mxn];
int Find(int x) {
if (ldr[x] == x) return x;
return ldr[x] = Find(ldr[x]);
}
void Union(int x, int y) {
x = Find(x), y = Find(y);
if (x == y) return;
if (rnk[y] > rnk[x]) swap(x, y);
rnk[x] += rnk[y];
ldr[y] = x;
}
int construct_roads(vector<int> x, vector<int> y) {
int n = x.size();
if (x.size() == 1) {
build({}, {}, {}, {});
return 1;
}
for (int i = 0; i < mxn; i++) ldr[i] = i, rnk[i] = 1;
vector<pair<int, int>> V;
for (int i = 0; i < n; i++) V.push_back({y[i], i});
sort(all(V));
for (int i = 0; i < n - 1; i++) {
if (V[i + 1].first - V[i].first > 2) return 0;
Union(V[i].second, V[i + 1].second);
}
set<int> s;
for (int i = 0; i < n; i++) s.insert(Find(i));
if (s.size() != 1) return 0;
vector<int> u, v, a, b;
for (int i = 0; i < n - 1; i++) {
u.push_back(V[i].second);
v.push_back(V[i + 1].second);
a.push_back(1);
b.push_back(V[i].first + 1);
}
build(u, v, a, b);
return 1;
}
