private void Tarjan(TarjanNodeModel vertex)
{
MakeSet(vertex);
vertex.Ancestor = vertex;
foreach (var child in vertex.Children)
{
Tarjan(child);
Union(vertex, child);
Find(vertex).Ancestor = vertex;
}
vertex.Color = Color.Black;
var targetPairs = _target.Where(x => x.Vertex1.Name == vertex.Name || x.Vertex2.Name == vertex.Name).ToList();
foreach (var pair in targetPairs)
{
var v = pair.Vertex1 == vertex ? pair.Vertex2 : pair.Vertex1;
if (v.Color == Color.Black)
{
var ancestor = Find(v).Ancestor.Name;
_result += $"({vertex.Name},{v.Name}) -> {ancestor}\n";
}
}
}
private void Union(TarjanNodeModel vertex1, TarjanNodeModel vertex2)
{
TarjanNodeModel largeRoot, smallRoot, vertexSmall, vertexLarge;
if (vertex1.Root.Count > vertex2.Root.Count)
{
largeRoot = vertex1.Root;
vertexLarge = vertex1;
smallRoot = vertex2.Root;
vertexSmall = vertex2;
}
else
{
largeRoot = vertex2.Root;
vertexLarge = vertex2;
smallRoot = vertex1.Root;
vertexSmall = vertex1;
}
smallRoot.Father = largeRoot;
largeRoot.Count = largeRoot.Count + smallRoot.Count;
smallRoot = largeRoot;
}
// return ancestor
private TarjanNodeModel Find(TarjanNodeModel vertex)
{
var list = new List <TarjanNodeModel>();
var currentVertex = vertex;
while (currentVertex.Father != null)
{
list.Add(currentVertex);
currentVertex = currentVertex.Father;
}
list.ForEach(v => v.Father = currentVertex);
return(currentVertex);
}
private void MakeSet(TarjanNodeModel vertex)
{
vertex.Father = null;
vertex.Count = 1;
}
