/*
Mayoeba Yabureru
*/
//#include "parks.h"
#include<bits/stdc++.h>
using namespace std;
static vector<int> _u, _v, _a, _b;
void build(vector<int> u, vector<int> v, vector<int> a, vector<int> b) {
_u = u;
_v = v;
_a = a;
_b = b;
}
int construct_roads(vector<int> x, vector<int> y) {
int n = x.size();
vector<vector<int>> gr(n + 1);
vector<int> dsu(n + 1);
map<pair<int, int>, int> mp;
map<pair<int, int>, pair<int, int>> mpp;
vector<pair<int, int>> vv;
x.insert(x.begin(), 0);
y.insert(y.begin(), 0);
for (int i = 1; i <= n; i ++) {
mp[{x[i], y[i]}] = i;
vv.push_back({x[i], y[i]});
dsu[i] = i;
}
vector<int> u, v, a, b;
map<pair<int, int>, int> taken;
map<pair<int, int>, int> connected;
function<int(int)> fp = [&](int x) {
if (dsu[x] == x) return x;
return dsu[x] = fp(dsu[x]);
};
sort(vv.begin(), vv.end());
for (int i = 0; i < n; i ++) {
auto xx = make_pair(vv[i].first, vv[i].second + 2);
if (mp[xx]) {
int fx = fp(mp[vv[i]]), fy = fp(mp[xx]);
if (fx != fy) {
u.push_back(mp[vv[i]]);
v.push_back(mp[xx]);
gr[mp[vv[i]]].push_back(mp[xx]);
gr[mp[xx]].push_back(mp[vv[i]]);
dsu[fx] = fy;
connected[{mp[vv[i]], mp[xx]}] = 1;
connected[{mp[xx], mp[vv[i]]}] = 1;
int ad = vv[i].second % 4;
mpp[{mp[vv[i]], mp[xx]}] = {vv[i].first - 1 + ad, vv[i].second + 1};
taken[{vv[i].first - 1 + ad, vv[i].second + 1}] = 1;
}
}
}
for (int i = 0; i < n; i ++) {
auto xx = make_pair(vv[i].first + 2, vv[i].second);
if (mp[xx]) {
int fx = fp(mp[vv[i]]), fy = fp(mp[xx]);
if (fx != fy) {
u.push_back(mp[vv[i]]);
v.push_back(mp[xx]);
gr[mp[vv[i]]].push_back(mp[xx]);
gr[mp[xx]].push_back(mp[vv[i]]);
dsu[fx] = fy;
connected[{mp[vv[i]], mp[xx]}] = 1;
connected[{mp[xx], mp[vv[i]]}] = 1;
if (taken[{vv[i].first + 1, vv[i].second + 1}] == 0) {
mpp[{mp[vv[i]], mp[xx]}] = {vv[i].first + 1, vv[i].second + 1};
taken[{vv[i].first + 1, vv[i].second + 1}] = 1;
}
else if (taken[{vv[i].first + 1, vv[i].second - 1}] == 0) {
mpp[{mp[vv[i]], mp[xx]}] = {vv[i].first + 1, vv[i].second - 1};
taken[{vv[i].first + 1, vv[i].second - 1}] = 1;
}
else assert(0);
}
}
}
int num = 0, st = 1;
vector<int> vis(n + 1);
function<void(int)> go = [&] (int v) {
num ++;
vis[v] = 1;
for (auto u : gr[v]) {
if (vis[u] == 0) go(u);
}
};
go(st);
for (int i = 0; i < u.size(); i ++) {
a.push_back(mpp[{u[i], v[i]}].first);
b.push_back(mpp[{u[i], v[i]}].second);
u[i] --;
v[i] --;
}
if (num == n) {
build(u, v, a, b);
return 1;
}
return 0;
}
int main() {
int n = 10000;
assert(scanf("%d", &n) == 1);
vector<int> x(n), y(n);
for (int i = 0; i < n; i++) assert(scanf("%d%d", &x[i], &y[i]) == 2);
const int possible = construct_roads(x, y);
printf("%d\n", possible);
if (possible == 1) {
int m = _u.size();
printf("%d\n", m);
for (int j = 0; j < m; j++) {
printf("%d %d %d %d\n", _u[j], _v[j], _a[j], _b[j]);
}
}
}
Compilation message
parks.cpp: In function 'int construct_roads(std::vector<int>, std::vector<int>)':
parks.cpp:96:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
96 | for (int i = 0; i < u.size(); i ++) {
| ~~^~~~~~~~~~
/usr/bin/ld: /tmp/ccyYK7yS.o: in function `build(std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >)':
grader.cpp:(.text+0x270): multiple definition of `build(std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >)'; /tmp/cctiAcQS.o:parks.cpp:(.text+0xbc0): first defined here
/usr/bin/ld: /tmp/ccyYK7yS.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cctiAcQS.o:parks.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status
