internal static void PerformWarshall(Internal.BitArray2D adj_matrix)
{
if (adj_matrix == null)
{
throw new System.ArgumentNullException(nameof(adj_matrix));
}
if (adj_matrix.Width != adj_matrix.Height)
{
const string msg = "Adjacency Matrix width must equal its height";
throw new System.ArgumentException(msg);
}
for (int k = 0; k < adj_matrix.Width; k++)
{
for (int row = 0; row < adj_matrix.Height; row++)
{
for (int col = 0; col < adj_matrix.Width; col++)
{
bool v = adj_matrix.Get(row, col) | (adj_matrix.Get(row, k) & adj_matrix.Get(k, col));
adj_matrix[row, col] = v;
}
}
}
}
internal static IEnumerable <DirectedEdge <A, object> > GetClosureFromEdges <A, B>(
IEnumerable <DirectedEdge <A, B> > edges)
{
if (edges == null)
{
throw new System.ArgumentNullException(nameof(edges));
}
var object_to_id = new Dictionary <A, int>();
var id_to_object = new Dictionary <int, A>();
foreach (var edge in edges)
{
if (!object_to_id.ContainsKey(edge.From))
{
object_to_id[edge.From] = object_to_id.Count;
}
if (!object_to_id.ContainsKey(edge.To))
{
object_to_id[edge.To] = object_to_id.Count;
}
}
foreach (var i in object_to_id)
{
id_to_object[i.Value] = i.Key;
}
var internal_edges = new List <DirectedEdge <int, object> >();
foreach (var edge in edges)
{
int fromid = object_to_id[edge.From];
int toid = object_to_id[edge.To];
var directed_edge = new DirectedEdge <int, object>(fromid, toid, null);
internal_edges.Add(directed_edge);
}
if (internal_edges.Count == 0)
{
yield break;
}
int num_vertices = object_to_id.Count;
var adj_matrix = new Internal.BitArray2D(num_vertices, num_vertices);
foreach (var iedge in internal_edges)
{
adj_matrix[iedge.From, iedge.To] = true;
}
var warshall_result = adj_matrix.Clone();
PathAnalysis.PerformWarshall(warshall_result);
for (int row = 0; row < adj_matrix.Width; row++)
{
for (int col = 0; col < adj_matrix.Height; col++)
{
if (warshall_result.Get(row, col) && (row != col))
{
var de = new DirectedEdge <A, object>(id_to_object[row], id_to_object[col], null);
yield return(de);
}
}
}
}
