#include <bits/stdc++.h>
using namespace std;
#define _ << " _ " <<
#define TRACE(x) cout << #x << " = " << x << endl
#define fi first
#define se second
typedef pair<int, int> pii;
typedef long long ll;
typedef long double ld;
const int MaxN = 2e5 + 10;
int n, x[MaxN], y[MaxN];
pair<int, int> line[MaxN];
ll ccw(int i, int j, int k) {
return (ll)x[i] * (y[j] - y[k]) +
(ll)x[j] * (y[k] - y[i]) +
(ll)x[k] * (y[i] - y[j]);
}
ll ccw0(int i, int j) {
return (ll)x[i] * y[j] - (ll)x[j] * y[i];
}
ll dist(int i) {
return (ll)x[i] * x[i] + (ll)y[i] * y[i];
}
bool equ(int i, int j) {
return (ll)y[i] * x[j] == (ll)y[j] * x[i];
}
bool pointCmp(int i, int j) {
if (equ(i, j)) return dist(i) < dist(j);
return (ll)y[i] * x[j] < (ll)y[j] * x[i];
}
bool eventCmp(pair<pii, int>& a, pair<pii, int>& b) {
if (equ(a.fi.fi, b.fi.fi) && a.se != b.se) return a.se < b.se;
return pointCmp(a.fi.fi, b.fi.fi);
}
bool above(int i, int j) {
int a = line[j].fi, b = line[j].se;
if (ccw0(a, b) == 0) return x[i] >= max(x[a], x[b]);
else if (i == a || i == b) return false;
else return (ccw0(a, i) < 0) || (ccw(a, b, i) < 0) || (ccw0(i, b) < 0);
}
struct lineCmp {
bool operator()(int i, int j) {
if (i == j) return false;
int a1 = line[i].fi, b1 = line[i].se;
int a2 = line[j].fi, b2 = line[j].se;
if (pointCmp(a1, a2) && pointCmp(a2, b1))
return above(a2, i);
else if (pointCmp(a1, b2) && pointCmp(b2, b1))
return above(b2, i);
else if (pointCmp(a2, a1) && pointCmp(a1, b2))
return !above(a1, j);
else if (pointCmp(a2, b1) && pointCmp(b1, b2))
return !above(b1, j);
else if (b1 == a2)
return false;
else if (b2 == a1)
return true;
}
};
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> n;
vector<pair<pii, int>> events;
for (int i = 0; i < n; i++) {
cin >> x[i] >> y[i];
events.push_back({{i, i}, 1});
}
for (int i = 0; i < n; i++) {
if (i == n - 1) line[i] = {i, 0};
else line[i] = {i, i + 1};
if (pointCmp(line[i].se, line[i].fi))
swap(line[i].fi, line[i].se);
events.push_back({{line[i].fi, i}, 0});
events.push_back({{line[i].se, i}, 2});
}
sort(events.begin(), events.end(), eventCmp);
multiset<int, lineCmp> lines;
vector<int> sol;
for (auto ev : events) {
if (ev.se == 0) {
lines.insert(ev.fi.se);
} else if (ev.se == 1) {
int i = ev.fi.se;
int j = *lines.begin();
if (!above(i, j)) sol.push_back(i);
} else {
lines.erase(ev.fi.se);
}
}
sort(sol.begin(), sol.end());
cout << sol.size() << "\n";
for (int i : sol) cout << i + 1 << " ";
return 0;
}
Compilation message
circuit.cpp: In member function 'bool lineCmp::operator()(int, int)':
circuit.cpp:73:5: warning: control reaches end of non-void function [-Wreturn-type]
}
^
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
380 KB |
Output is correct |
| 2 |
Correct |
3 ms |
488 KB |
Output is correct |
| 3 |
Correct |
5 ms |
756 KB |
Output is correct |
| 4 |
Correct |
6 ms |
948 KB |
Output is correct |
| 5 |
Correct |
18 ms |
1156 KB |
Output is correct |
| 6 |
Correct |
18 ms |
1188 KB |
Output is correct |
| 7 |
Correct |
41 ms |
1708 KB |
Output is correct |
| 8 |
Correct |
15 ms |
1708 KB |
Output is correct |
| 9 |
Correct |
23 ms |
1708 KB |
Output is correct |
| 10 |
Correct |
19 ms |
1708 KB |
Output is correct |
| 11 |
Correct |
24 ms |
1708 KB |
Output is correct |
| 12 |
Correct |
31 ms |
1800 KB |
Output is correct |
| 13 |
Correct |
78 ms |
2696 KB |
Output is correct |
| 14 |
Correct |
84 ms |
2812 KB |
Output is correct |
| 15 |
Correct |
91 ms |
4604 KB |
Output is correct |
| 16 |
Execution timed out |
134 ms |
8308 KB |
Time limit exceeded |
| 17 |
Execution timed out |
288 ms |
8308 KB |
Time limit exceeded |
| 18 |
Execution timed out |
325 ms |
16012 KB |
Time limit exceeded |
| 19 |
Execution timed out |
321 ms |
16012 KB |
Time limit exceeded |
| 20 |
Execution timed out |
786 ms |
16012 KB |
Time limit exceeded |
