private static string E(IndexedIncidenceGraph g, int e)
{
string head = g.TryGetHead(e, out int h) ? V(h) : "?";
string tail = g.TryGetTail(e, out int t) ? V(t) : "?";
return(string.Concat(tail, " -> ", head));
}
public void GlobalSetup()
{
Graph = GraphHelper.Default.GetGraph(VertexCount);
_compactExploredSet = ArrayPool <byte> .Shared.Rent(CompactSet.GetByteCount(Graph.VertexCount));
_fastExploredSet = ArrayPool <byte> .Shared.Rent(Graph.VertexCount);
}
private static void DemoShuffle()
{
IndexedIncidenceGraph.Builder builder = new(10);
using (TextReader textReader = IndexedGraphs.GetTextReader("08"))
{
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;
w.WriteLine("digraph Shuffled {");
w.WriteLine(" node [shape=circle fontname=\"Times-Italic\"]");
// Enumerate vertices.
for (int v = 0; v < graph.VertexCount; ++v)
{
w.Write(v == 0 ? " " : " ");
w.Write(V(v));
}
w.WriteLine();
int[] permutation = Enumerable.Range(0, graph.EdgeCount)
.OrderBy(i => new Random(i).Next()).ToArray();
for (int i = 0; i < graph.EdgeCount; ++i)
{
int e = permutation[i];
w.Write(" ");
w.Write(E(graph, e));
w.WriteLine($" [label={i.ToString(F)}]");
}
w.WriteLine("}");
}
private static IndexedIncidenceGraph GenerateIncidenceGraph(int vertexCount, double densityPower)
{
int edgeCount = (int)Math.Ceiling(Math.Pow(vertexCount, densityPower));
IndexedIncidenceGraph.Builder builder = new(vertexCount);
Random prng = new(1729);
for (int e = 0; e < edgeCount; ++e)
{
int tail = prng.Next(vertexCount);
int head = prng.Next(vertexCount);
builder.Add(tail, head);
}
IndexedIncidenceGraph result = builder.ToGraph();
return(result);
}
private static void DemoRecursiveDfs()
{
const int vertexCount = 10000;
const double densityPower = 1.5;
IndexedIncidenceGraph graph = GenerateIncidenceGraph(vertexCount, densityPower);
byte[] backingStore = ArrayPool <byte> .Shared.Rent(vertexCount);
Array.Clear(backingStore, 0, backingStore.Length);
IndexedColorDictionary colorMap = new(backingStore);
List <int> steps = new();
DfsHandler <IndexedIncidenceGraph, int, int> dfsHandler = CreateDfsHandler(steps);
RecursiveDfs <IndexedIncidenceGraph, int, int, EdgeEnumerator> dfs = default;
dfs.Traverse(graph, 0, colorMap, dfsHandler);
Console.WriteLine(steps.Count);
ArrayPool <byte> .Shared.Return(backingStore, true);
}
private static void Main()
{
IndexedIncidenceGraph.Builder builder = new(0, 31);
using (TextReader textReader = IndexedGraphs.GetTextReader("09"))
{
IEnumerable <Endpoints> edges = IndexedEdgeListParser.ParseEdges(textReader);
foreach (Endpoints edge in edges)
{
builder.Add(edge.Tail, edge.Head);
}
}
IndexedIncidenceGraph graph = builder.ToGraph();
Console.Write($"{nameof(graph.VertexCount)}: {graph.VertexCount.ToString(F)}");
Console.WriteLine($", {nameof(graph.EdgeCount)}: {graph.EdgeCount.ToString(F)}");
TextWriter w = Console.Out;
EagerBfs <IndexedIncidenceGraph, int, int, ArraySegment <int> .Enumerator> bfs = default;
w.WriteLine($"digraph \"{bfs.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);
BfsHandler <IndexedIncidenceGraph, int, int> handler = CreateHandler(w, examinedEdges);
bfs.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("}");
}
