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[Trần Anh <>]

Hi all,

I hope I can get a bit of advice on this. I have a soup of edges and I would like to remove all edge that have a vertex degree one. I end up choosing 2D Arrangement package to do so (see below). My first attempt is to iterate through all the edge and delete the ones that meet the condition. I soon realised that when I delete one edge, I make another edge that previously does not meet the condition now meet it. So I decided to create a std::vector<Halfedge_handle> to store all the edge (iterator) and later delete them from the arrangement all at once. Apparently converting between Halfedge_handle and Edge_iterator is not possible.

Is there any solution to this? Or is there any better solution than using Arrangement? Thanks :).

#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Polygon_2.h>
#include <CGAL/Cartesian.h>
#include <CGAL/MP_Float.h>
#include <CGAL/Quotient.h>
#include <CGAL/Arr_segment_traits_2.h>
#include <CGAL/Arrangement_2.h>

#include <iostream>

typedef CGAL::Quotient<CGAL::MP_Float> Number_type;
typedef CGAL::Cartesian<Number_type> Kernel;
typedef CGAL::Arr_segment_traits_2<Kernel> Traits_2;
typedef Traits_2::Point_2 Point_2;
typedef Traits_2::X_monotone_curve_2 Curve_2;
typedef CGAL::Arrangement_2<Traits_2> Arrangement_2;

int main()
{
	Point_2 p0(0, 0), p1(0, 1), p2(1, 1), p3(1, 2), p4(2, 2);
	Curve_2 c0(p0, p1), c1(p1, p2), c2(p2, p3), c3(p2, p4);

	std::vector<Curve_2> curves;
	curves.push_back(c0);
	curves.push_back(c1);
	curves.push_back(c2);
	curves.push_back(c3);

	Arrangement_2 arr;
	Arrangement_2::Edge_iterator eit;
	CGAL::insert(arr, curves.begin(), curves.end());

	for (eit = arr.edges_begin(); eit != arr.edges_end(); ++eit)
	{
		if ((eit->source()->degree() == 1) || (eit->target()->degree()))
		{
			arr.remove_edge(eit);
		}
	}
	std::cout << arr.number_of_edges() << std::endl;
	return 1;

}