public DirectedGraph Clone()
{
var result = new DirectedGraph();
foreach (var node in _nodes)
{
var newNode = new Node(node.Name);
result.AddNode(newNode);
}
foreach (var edge in _edges)
{
result.Connect(edge.Source.Name, edge.Target.Name);
}
return result;
}
void tarjan(Node v, DirectedGraph graph)
{
v.SetIndex(_index);
v.SetLowLink(_index);
_index++;
_stack.Push(v);
foreach (var n in graph.GetTargetsForSource(v))
{
if (n.Index == -1)
{
tarjan(n, graph);
var lowLink = Math.Min(v.LowLink, n.LowLink);
v.SetLowLink(lowLink);
}
else if (_stack.Contains(n))
{
var lowLink = Math.Min(v.LowLink, n.Index);
v.SetLowLink(lowLink);
}
}
if(v.LowLink == v.Index)
{
var cycle = new Cycle();
Node n;
do
{
n = _stack.Pop();
cycle.Add(n);
} while (!v.Equals(n));
_cycles.Add(cycle);
}
}
public IEnumerable<Node> Order(DirectedGraph graph)
{
_graph = graph.Clone();
while(!_graph.IsEmpty())
{
var nodes = _graph.GetEntryNodes();
foreach (var node in nodes)
{
visit(node);
}
}
return _order;
}
public IEnumerable<Cycle> FindCycles(DirectedGraph graph)
{
foreach (var node in graph._nodes)
tarjan(node, graph);
return _cycles;
}