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  1. #include <algorithm>
  2. #include <iostream>
  3. #include <vector>
  4. #include <set>
  5. using namespace std;
  6. const int MAX = 200005;
  7. pair<int, int> p[MAX];
  8. vector<pair<int, int> > v;
  9. int a[MAX], b[MAX];
  10. pair<long long, long long> intersect(pair<int, int> a, pair<int, int> b)
  11. {
  12. 	return make_pair(a.first * (b.second - a.second), a.second * (b.first - a.first));
  13. }
  14. bool cmp(pair<long long, long long> a, pair<long long, long long> b)
  15. {
  16. 	return (a.first * b.second < a.second * b.first);
  17. }
  18. int main()
  19. {
  20. 	ios::sync_with_stdio(false);
  21. 	int n;
  22. 	cin >> n;
  23. 	int tn = n;
  24. 	for (int i = 0; i < n; i++)
  25. 	{
  26. 		cin >> p[i].first >> p[i].second;
  27. 		a[i] = p[i].first;
  28. 		b[i] = p[i].second;
  29. 	}
  30. 	sort(p, p + n);
  31. 	for (int i = 0; i < n; i++)
  32. 	{
  33. 		while (!v.empty() && v.back().second <= p[i].second)
  34. 			v.pop_back();
  35. 		v.push_back(p[i]);
  36. 	}
  37. 	n = v.size();
  38. 	for (int i = 0; i < n; i++)
  39. 		p[i] = v[i];
  40. 	v.clear();
  41. 	for (int i = 0; i < n; i++)
  42. 	{
  43. 		while (v.size() > 1 && cmp(intersect(p[i], v.back()), intersect(v[v.size() - 2], v.back())))
  44. 			v.pop_back();
  45. 		v.push_back(p[i]);
  46. 	}
  47. 	set<pair<int, int> > s;
  48. 	for (int i = 0; i < v.size(); i++)
  49. 		s.insert(v[i]);
  50. 	vector<int> ans;
  51. 	for (int i = 0; i < tn; i++)
  52. 		if (s.count(make_pair(a[i], b[i])))
  53. 			ans.push_back(i + 1);
  54. 	for (int i = 0; i < ans.size(); i++)
  55. 		cout << ans[i] << " ";
  56. 	cout << endl;
  57. 	return 0;
  58. }
Runtime error #stdin #stdout 0s 6360KB
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https://ideone.com/PTMgaW
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
secret

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