Translating concave hull algorithm to c#

Question

So I am trying to translate the algorith found here for concave hulls: http://repositorium.sdum.uminho.pt/bitstream/1822/6429/1/ConcaveHull_ACM_MYS.pdf

(Page 65)

Answer 1

You have error in

private static Vertex[] nearestPoints(Vertex[] vs, Vertex v, int k)
{
    Dictionary lengths = new Dictionary();
    List n = new List();
    double[] sorted = lengths.Keys.OrderBy(d => d).ToArray();
    for (int i = 0; i < k; i++)
    {
        n.Add(lengths[sorted[i]]);
    }
    return n.ToArray();
}

according to code if you have several vertexes at the same distance, function returns only one. Since Dictionary uses unique keys.

BTW, did anyone finish this?