private void DfsTopoSCC(KosarajuNode currentNode, Dictionary <long, KosarajuNode> nodeById)
{
currentNode.Explored = true;
currentNode.SCCNumber = numSCC;
foreach (var currentNodeAdjacentNodeId in currentNode.AdjacentNodeIds)
{
var nextNode = nodeById[currentNodeAdjacentNodeId];
if (!nextNode.Explored)
{
DfsTopoSCC(nextNode, nodeById);
}
}
}
private void DfsTopo(KosarajuNode currentNode, Dictionary <long, KosarajuNode> nodeById,
KosarajuNode[] secondIterationCollection)
{
currentNode.Explored = true;
foreach (var currentNodeAdjacentNodeId in currentNode.RevAdjacentNodeIds)
{
var nextNode = nodeById[currentNodeAdjacentNodeId];
if (!nextNode.Explored)
{
DfsTopo(nextNode, nodeById, secondIterationCollection);
}
}
rankNew = rankNew + 1;
currentNode.CurrentLabel = rankNew;
secondIterationCollection[rankNew - 1] = currentNode;
//rankNew -= 1;
}
private void Dowork()
{
try
{
var nodeById = nodes.ToDictionary(node => node.Id);
var orderedNode = nodeById.Values.OrderByDescending(node => node.Id);
Stack <KosarajuNode> processingNodesStack = new Stack <KosarajuNode>();
long rank = 0;
var secondIterationCollection = new KosarajuNode[nodeById.Values.Count];
rankNew = 0; // nodeById.Values.Count;
foreach (var currentOuterNode in orderedNode)
{
if (!currentOuterNode.Explored)
{
DfsTopo(currentOuterNode, nodeById, secondIterationCollection);
}
}
secondIterationCollection = secondIterationCollection.ToList().Select(node =>
{
node.Explored = false;
return(node);
}).ToArray();
numSCC = 0;
for (int i = secondIterationCollection.Length - 1; i >= 0; i--)
{
var currentOuterNode = secondIterationCollection[i];
if (!currentOuterNode.Explored)
{
numSCC = numSCC + 1;
DfsTopoSCC(currentOuterNode, nodeById);
}
}
}
catch (Exception e)
{
Console.WriteLine(e);
throw;
}
}
public void Run(IEnumerable <KosarajuNode> graphNodes)
{
var nodeById = graphNodes.ToDictionary(node => node.Id);
var orderedNode = nodeById.Values.OrderByDescending(node => node.Id);
Stack <KosarajuNode> processingNodesStack = new Stack <KosarajuNode>();
long rank = 0;
var secondIterationCollection = new KosarajuNode[nodeById.Values.Count];
foreach (var currentOuterNode in orderedNode)
{
if (currentOuterNode.Explored)
{
continue;
}
processingNodesStack.Push(currentOuterNode);
while (processingNodesStack.Count > 0)
{
var currentNode = processingNodesStack.Pop();
if (currentNode.Explored)
{
if (currentNode.CurrentLabel != 0)
{
continue;
}
rank += 1;
currentNode.CurrentLabel = rank;
secondIterationCollection[rank - 1] = currentNode;
continue;
}
currentNode.Explored = true;
processingNodesStack.Push(currentNode);
foreach (var currentNodeRevAdjacentNodeId in currentNode.RevAdjacentNodeIds)
{
var nextNode = nodeById[currentNodeRevAdjacentNodeId];
if (nextNode.Explored)
{
continue;
}
processingNodesStack.Push(nextNode);
}
}
}
secondIterationCollection = secondIterationCollection.ToList().Select(node =>
{
node.Explored = false;
return(node);
}).ToArray();
var sccNumber = 0;
for (int i = secondIterationCollection.Length - 1; i >= 0; i--)
{
var currentOuterNode = secondIterationCollection[i];
if (currentOuterNode.Explored)
{
continue;
}
sccNumber += 1;
processingNodesStack.Push(currentOuterNode);
while (processingNodesStack.Count > 0)
{
var currentNode = processingNodesStack.Pop();
if (currentNode.Explored)
{
currentNode.SCCNumber = sccNumber;
continue;
}
currentNode.Explored = true;
processingNodesStack.Push(currentNode);
foreach (var currentNodeAdjacentNodeId in currentNode.AdjacentNodeIds)
{
var nextNode = nodeById[currentNodeAdjacentNodeId];
if (nextNode.Explored)
{
continue;
}
processingNodesStack.Push(nextNode);
}
}
}
}
