/// <summary>
/// Find all paths starting with the given node
/// </summary>
/// <param name="node">Starting node</param>
public void SearchFrom(NodeType node)
{
stack.Push(node);
isBlocked[node] = true;
bool canExtend = false;
foreach (NodeType target in graph.TargetsOf(node))
{
if (isBlocked[target])
{
continue;
}
// recursive call
SearchFrom(target);
canExtend = true;
}
isBlocked[node] = false;
if (!canExtend && stack.Count > 1)
{
// path has multiple nodes and cannot be extended
OnBeginPath();
Stack <NodeType> temp = new Stack <NodeType>();
foreach (NodeType nodeOnStack in stack)
{
temp.Push(nodeOnStack);
}
foreach (NodeType nodeOnStack in temp)
{
OnAddNode(nodeOnStack);
}
OnEndPath();
}
stack.Pop();
}
/// <summary>
/// Find cycles containing root
/// </summary>
/// <param name="node"></param>
/// <param name="root"></param>
/// <returns></returns>
private bool SearchFrom(NodeType node, NodeType root)
{
bool foundCycle = false;
stack.Push(node);
isBlocked[node] = true;
foreach (NodeType target in graph.TargetsOf(node))
{
if (excluded.Contains(target))
{
continue;
}
if (target.Equals(root))
{
foundCycle = true;
OnBeginCycle();
Stack <NodeType> temp = new Stack <NodeType>();
foreach (NodeType nodeOnStack in stack)
{
temp.Push(nodeOnStack);
}
foreach (NodeType nodeOnStack in temp)
{
OnAddNode(nodeOnStack);
}
OnEndCycle();
}
else if (!isBlocked[target])
{
// recursive call
if (SearchFrom(target, root))
{
foundCycle = true;
}
}
}
// at this point, we could always set isBlocked[node]=false,
// but as an optimization we leave it set if no cycle was discovered,
// to prevent repeated searching of the same paths.
if (foundCycle)
{
Unblock(node);
}
else
{
// at this point, all targets are blocked
foreach (NodeType target in graph.TargetsOf(node))
{
if (excluded.Contains(target))
{
continue;
}
Set <NodeType> blockedSourcesOfTarget = blockedSources[target];
if (blockedSourcesOfTarget == null)
{
blockedSourcesOfTarget = new Set <NodeType>();
blockedSources[target] = blockedSourcesOfTarget;
}
blockedSourcesOfTarget.Add(node);
}
}
stack.Pop();
return(foundCycle);
}
