#include <bits/stdc++.h>
using namespace std;
vector<pair<int, int>> v;
int dx[8] = {-1, -1, -1, 0, 1, 1, 1, 0};
int dy[8] = {-1, 0, 1, 1, 1, 0, -1, -1};
int dxe[4] = {-1, 0, 1, 0};
int dye[4] = {0, 1, 0, -1};
map<pair<int, int>, int> m;
set<pair<int, int>> black;
struct dsu {
vector<int> par, siz;
void init(int n) {
vector<int>().swap(par);
vector<int>().swap(siz);
par.resize(n);
siz.resize(n, 1);
for(int i = 0; i < n; i++) par[i] = i;
}
int get(int x) {
if(x == par[x]) return x;
return par[x] = get(par[x]);
}
bool unite(int x, int y) {
x = get(x);
y = get(y);
if(x == y) return false;
if(x < y) swap(x, y); // y is the lesser one now
par[x] = y;
siz[y] += siz[x];
return true;
}
};
vector<int> find_order(int n, vector<int> x, vector<int> y) {
vector<int> ans;
return ans;
}
vector<int> find_best_order(int n, vector<int> x, vector<int> y) {
vector<int> ans;
int mix, miy;
mix = miy = 1234567890;
for(int i = 0; i < n; i++) {
mix = min(mix, x[i]);
miy = min(miy, y[i]);
}
mix--;
miy--;
for(int i = 0; i < n; i++) {
x[i] -= mix;
y[i] -= miy;
v.push_back({x[i], y[i]});
black.insert({x[i], y[i]});
for(int j = 0; j < 8; j++) {
v.push_back({x[i]+dx[j], y[i]+dy[j]});
}
}
sort(v.begin(), v.end());
v.erase(unique(v.begin(), v.end()), v.end());
// Vertex labels are stored as an unordered_map
// I should constopt this if it's too slow
for(int i = 0; i < v.size(); i++) {
m[v[i]] = i;
}
dsu uf;
uf.init(v.size()+1);
// First check if the peple are connected
bool ok = false;
for(int i = 0; i < v.size(); i++) {
if(black.count(v[i])) {
for(int j = 0; j < 8; j++) {
pair<int, int> oth_pair = {v[i].first+dx[j], v[i].second+dy[j]};
if(black.count(oth_pair)) {
uf.unite(m[v[i]], m[oth_pair]);
}
}
if(uf.siz[uf.get(m[v[i]])] == n) ok = true;
}
}
if(!ok) return ans;
// Now find an order, unite all white regions
uf.init(v.size()+1);
for(int i = 0; i < v.size(); i++) {
if(black.count(v[i])) continue;
for(int j = 0; j < 4; j++) {
pair<int, int> oth_pair = {v[i].first+dxe[j], v[i].second+dye[j]};
if(black.count(oth_pair)) continue;
uf.unite(m[v[i]], m[oth_pair]);
}
}
ans.reserve(n);
for(int z = 0; z < n; z++) {
for(int i = 0; i < n; i++) { // Checks if the regions around the cell are "good"
pair<int, int> this_pair = {x[i], y[i]};
// cout << x[i] << ' ' << y[i] << '\n';
if(!black.count(this_pair)) continue;
vector<int> regs;
for(int j = 0; j < 4; j++) {
pair<int, int> oth_pair = {x[i]+dxe[j], y[i]+dye[j]};
if(black.count(oth_pair)) regs.push_back(-1);
else regs.push_back(uf.get(m[oth_pair]));
oth_pair = {x[i]+dx[2*j], y[i]+dy[2*j]};
if(black.count(oth_pair)) regs.push_back(-1);
}
/*
cout << z << ' ' << i << " | ";
for(int g : regs) cout << g << ' ';
cout << '\n';
*/
regs.erase(unique(regs.begin(), regs.end()), regs.end());
regs.erase(remove(regs.begin(), regs.end(), -1), regs.end());
remove(regs.begin(), regs.end(), -1);
if(regs.size() == 1 && regs[0] == 0) {
black.erase(this_pair);
ans.push_back(i+1);
uf.unite(m[this_pair], 0);
break;
}
if(regs.size() == 1) continue;
if(regs[0] == regs.back()) regs.pop_back();
sort(regs.begin(), regs.end());
if(regs[0] != 0) continue;
bool ok = true;
for(int i = 1; i < regs.size(); i++) {
if(regs[i] == regs[i-1]) ok = false;
}
if(!ok) continue;
black.erase(this_pair);
ans.push_back(i+1);
uf.unite(m[this_pair], 0);
for(int i = 1; i < regs.size(); i++) {
uf.unite(regs[i-1], regs[i]);
}
break;
}
if(ans.size() == z-1) {
vector<int>().swap(ans);
return ans;
}
}
reverse(ans.begin(), ans.end());
return ans;
}
int main() {
int n, s;
cin >> n >> s;
vector<int> x(n), y(n);
for(int i = 0; i < n; i++) {
cin >> x[i] >> y[i];
}
vector<int> ans;
if(s == 1) ans = find_best_order(n, x, y);
if(s == 2) ans = find_best_order(n, x, y);
if(ans.size() == 0) {
cout << "NO\n";
}
else {
cout << "YES\n";
for(int i = 0; i < ans.size(); i++) cout << ans[i] << '\n';
}
}
Compilation message
skyscrapers.cpp: In function 'std::vector<int> find_best_order(int, std::vector<int>, std::vector<int>)':
skyscrapers.cpp:68:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
68 | for(int i = 0; i < v.size(); i++) {
| ~~^~~~~~~~~~
skyscrapers.cpp:75:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
75 | for(int i = 0; i < v.size(); i++) {
| ~~^~~~~~~~~~
skyscrapers.cpp:89:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
89 | for(int i = 0; i < v.size(); i++) {
| ~~^~~~~~~~~~
skyscrapers.cpp:130:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
130 | for(int i = 1; i < regs.size(); i++) {
| ~~^~~~~~~~~~~~~
skyscrapers.cpp:137:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
137 | for(int i = 1; i < regs.size(); i++) {
| ~~^~~~~~~~~~~~~
skyscrapers.cpp:142:23: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
142 | if(ans.size() == z-1) {
| ~~~~~~~~~~~^~~~~~
skyscrapers.cpp: In function 'int main()':
skyscrapers.cpp:166:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
166 | for(int i = 0; i < ans.size(); i++) cout << ans[i] << '\n';
| ~~^~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
204 KB |
ans=YES N=1 |
| 2 |
Correct |
1 ms |
204 KB |
ans=YES N=4 |
| 3 |
Correct |
1 ms |
204 KB |
ans=NO N=4 |
| 4 |
Incorrect |
0 ms |
204 KB |
Full cells must be connected |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
204 KB |
ans=YES N=1 |
| 2 |
Correct |
1 ms |
204 KB |
ans=YES N=4 |
| 3 |
Correct |
1 ms |
204 KB |
ans=NO N=4 |
| 4 |
Incorrect |
0 ms |
204 KB |
Full cells must be connected |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
204 KB |
ans=YES N=1 |
| 2 |
Correct |
1 ms |
204 KB |
ans=YES N=4 |
| 3 |
Correct |
1 ms |
204 KB |
ans=NO N=4 |
| 4 |
Incorrect |
0 ms |
204 KB |
Full cells must be connected |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
10 ms |
1700 KB |
ans=NO N=1934 |
| 2 |
Correct |
7 ms |
968 KB |
ans=NO N=1965 |
| 3 |
Incorrect |
318 ms |
716 KB |
Full cells must be connected |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
204 KB |
ans=YES N=1 |
| 2 |
Correct |
1 ms |
204 KB |
ans=YES N=4 |
| 3 |
Correct |
1 ms |
204 KB |
ans=NO N=4 |
| 4 |
Incorrect |
0 ms |
204 KB |
Full cells must be connected |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
267 ms |
16544 KB |
ans=NO N=66151 |
| 2 |
Correct |
333 ms |
40648 KB |
ans=NO N=64333 |
| 3 |
Execution timed out |
3593 ms |
14620 KB |
Time limit exceeded |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
10 ms |
1700 KB |
ans=NO N=1934 |
| 2 |
Correct |
7 ms |
968 KB |
ans=NO N=1965 |
| 3 |
Incorrect |
318 ms |
716 KB |
Full cells must be connected |
| 4 |
Halted |
0 ms |
0 KB |
- |
