private static Graph RandomConnectedGraphInternal(int vertexCount, int edgeCount, Random random)
{
var ids = Enumerable.Range(0, vertexCount);
var graph = new MutableGraph();
graph.Vertices.AddRange(VerticesInIdRange(0, vertexCount));
var vertices = graph.Vertices.ToDictionary(v => v.Id);
// making graph connected
foreach (var id in ids)
{
var otherId = random.Next(id);
if (id > 0)
{
var edge = new MutableEdge {
Vertex1 = vertices[id], Vertex2 = vertices[otherId], Label = $"e{id}:{otherId}"
};
graph.Edges.Add(edge);
}
}
// adding remaining vertices
foreach (var edgeId in Enumerable.Range(vertexCount, edgeCount - vertexCount + 1))
{
var id1 = random.Next(vertexCount);
var id2 = random.Next(vertexCount);
var edge = new MutableEdge {
Vertex1 = vertices[id1], Vertex2 = vertices[id2], Label = $"e{id1}:{id2}"
};
graph.Edges.Add(edge);
}
return(graph.ToImmutable());
}
public static Graph ToImmutable(this MutableGraph mutable)
{
var vertices = mutable.Vertices.Select(v => v.ToImmutable()).ToImmutableSortedSet();
var index = new Graph(vertices, ImmutableSortedSet.Create <Edge>()).Index();
var edges = mutable.Edges.Select(e => e.ToImmutable(index)).ToImmutableSortedSet();
return(new Graph(vertices, edges));
}
/// <summary>
/// Adds to <paramref name="graph"/> new edges connecting each of <paramref name="vertices"/> with every other.
/// </summary>
/// <param name="graph">Graph to add edges to.</param>
/// <param name="vertices">Vertices to connect with new edges.</param>
public static void ConnectAll(this MutableGraph graph, IEnumerable <MutableVertex> vertices)
{
graph.ConnectAll(vertices.ToArray());
}
/// <summary>
/// Adds to <paramref name="graph"/> new edges connecting each of <paramref name="vertices"/> with every other.
/// </summary>
/// <param name="graph">Graph to add edges to.</param>
/// <param name="vertices">Vertices to connect with new edges.</param>
public static void ConnectAll(this MutableGraph graph, params MutableVertex[] vertices)
{
graph.Edges.AddRange(vertices.SelectMany(v1 => vertices.Select(v2 => v1.Id != v2.Id ? v1.Connecting(v2) : null).Where(e => e != null)));
}
