private void EnumerateEdgesCore(Graph graph, bool multipleSource)
{
// Arrange
byte[] mapBackingStore = ArrayPool <byte> .Shared.Rent(Math.Max(graph.VertexCount, 1));
Array.Clear(mapBackingStore, 0, mapBackingStore.Length);
IndexedColorDictionary eagerColorMap = new(mapBackingStore);
byte[] setBackingStore = ArrayPool <byte> .Shared.Rent(Math.Max(graph.VertexCount, 1));
Array.Clear(setBackingStore, 0, setBackingStore.Length);
IndexedSet set = new(setBackingStore);
using Rist <int> eagerSteps = new(graph.VertexCount);
using Rist <int> enumerableSteps = new(graph.VertexCount);
DfsHandler <Graph, int, int> dfsHandler = CreateDfsHandler(eagerSteps);
// Act
if (multipleSource)
{
if (graph.VertexCount < 3)
{
return;
}
int sourceCount = graph.VertexCount / 3;
IndexEnumerator sources = new(sourceCount);
EagerDfs.Traverse(graph, sources, eagerColorMap, dfsHandler);
using IEnumerator <int> edges = EnumerableDfs.EnumerateEdges(graph, sources, set);
enumerableSteps.AddEnumerator(edges);
}
else
{
int source = graph.VertexCount >> 1;
EagerDfs.Traverse(graph, source, eagerColorMap, dfsHandler);
using IEnumerator <int> edges = EnumerableDfs.EnumerateEdges(graph, source, set);
enumerableSteps.AddEnumerator(edges);
}
// Assert
int eagerStepCount = eagerSteps.Count;
int enumerableStepCount = enumerableSteps.Count;
Assert.Equal(eagerStepCount, enumerableStepCount);
int count = eagerStepCount;
for (int i = 0; i < count; ++i)
{
int eagerStep = eagerSteps[i];
int enumerableStep = enumerableSteps[i];
if (eagerStep == enumerableStep)
{
continue;
}
Assert.Equal(eagerStep, enumerableStep);
}
// Cleanup
ArrayPool <byte> .Shared.Return(mapBackingStore);
ArrayPool <byte> .Shared.Return(setBackingStore);
}
private static void Main()
{
IndexedIncidenceGraph.Builder builder = new(0, 31);
using (TextReader textReader = IndexedGraphs.GetTextReader("09"))
{
IEnumerable <Endpoints> edges = IndexedEdgeListParser.ParseEdges(textReader);
foreach (Endpoints edge in edges)
{
builder.Add(edge.Tail, edge.Head);
}
}
IndexedIncidenceGraph graph = builder.ToGraph();
Console.Write($"{nameof(graph.VertexCount)}: {graph.VertexCount.ToString(F)}");
Console.WriteLine($", {nameof(graph.EdgeCount)}: {graph.EdgeCount.ToString(F)}");
TextWriter w = Console.Out;
EagerDfs <IndexedIncidenceGraph, int, int, ArraySegment <int> .Enumerator> dfs = default;
w.WriteLine($"digraph \"{dfs.GetType().Name}\" {{");
w.WriteLine(" node [shape=circle style=dashed fontname=\"Times-Italic\"]");
// Enumerate vertices.
for (int v = 0; v < graph.VertexCount; ++v)
{
w.Write(v == 0 ? " " : " ");
w.Write(V(v));
}
w.WriteLine();
IndexEnumerator sources = new(2);
byte[] backingStore = ArrayPool <byte> .Shared.Rent(graph.VertexCount);
Array.Clear(backingStore, 0, backingStore.Length);
IndexedColorDictionary colorMap = new(backingStore);
HashSet <int> examinedEdges = new(graph.EdgeCount);
DfsHandler <IndexedIncidenceGraph, int, int> handler = CreateHandler(w, examinedEdges);
dfs.Traverse(graph, sources, colorMap, handler);
ArrayPool <byte> .Shared.Return(backingStore);
// Enumerate sources.
w.WriteLine();
sources.Reset();
while (sources.MoveNext())
{
int v = sources.Current;
w.WriteLine($" {V(v)} [style=filled]");
}
// Enumerate rest of edges.
w.WriteLine();
for (int v = 0; v < graph.VertexCount; ++v)
{
ArraySegment <int> .Enumerator outEdges = graph.EnumerateOutEdges(v);
while (outEdges.MoveNext())
{
int e = outEdges.Current;
if (examinedEdges.Contains(e))
{
continue;
}
w.WriteLine($" {E(graph, e)} [label={e} style=dotted]");
}
}
w.WriteLine("}");
}