private void DfsRec(Digraph digraph, int v)
{
//preOrder.Enqueue(v);
visited[v] = true;
foreach (int w in digraph.Adjacent(v)) // 6 1 5
{
if (!visited[w])
{
DfsRec(digraph, w);
}
}
//postOrder.Enqueue(v);
reversePostOrder.Push(v);
}
public DepthFirstOrder(Digraph digraph)
{
//preOrder = new Queue<int>();
//postOrder = new Queue<int>();
reversePostOrder = new Stack <int>();
visited = new bool[digraph.NodeCount];
inStack = new bool[digraph.NodeCount];
for (int v = 0; v < digraph.NodeCount; v++)
{
if (!visited[v])
{
Dfs(digraph, v);
}
}
}
private void Dfs(Digraph digraph, int source)
{
Stack <int> stack = new Stack <int>();
stack.Push(source);
visited[source] = true;
while (stack.Count != 0)
{
int v = stack.Pop();
foreach (var w in digraph.Adjacent(v))
{
if (!visited[w])
{
visited[w] = true;
stack.Push(w);
}
}
}
}
public DirectCycles(Digraph digraph)
{
int nodeCount = digraph.NodeCount;
visited = new bool[nodeCount];
cycledPaths = new Dictionary <int, int[]>();
edgeTo = new int[nodeCount];
onStack = new bool[nodeCount];
for (int inx = 0; inx < nodeCount; inx++)
{
edgeTo[inx] = -1;
}
for (int s = 0; s < nodeCount; s++)
{
if (!visited[s])
{
Dfs(digraph, s);
}
}
}
private void Dfs(Digraph digraph, int s)
{
bool[] onPath = new bool[digraph.NodeCount];
Stack <int> stack = new Stack <int>();
stack.Push(s);
visited[s] = true;
onPath[s] = true;
while (stack.Count != 0)
{
int v = stack.Pop();
//onPath[v] = false;
Console.WriteLine(v);
foreach (int w in digraph.Adjacent(v))
{
if (!visited[w])
{
edgeTo[w] = v;
onPath[w] = true;
visited[w] = true;
stack.Push(w);
}
else if (onPath[w]) // already went through
{
Stack <int> tmp = new Stack <int>();
for (int x = v; x != w && x != -1; x = edgeTo[x])
{
tmp.Push(x);
}
tmp.Push(w);
tmp.Push(v);
cycledPaths[cycledPaths.Count] = tmp.ToArray();
}
}
}
}
private bool Dfs(Digraph digraph, int s)
{
Stack <int> stack = new Stack <int>();
stack.Push(s);
while (stack.Count > 0)
{
int node = stack.Peek();
visited[node] = true;
inStack[node] = true;
IList <int> adjs = digraph.Adjacent(node);
int aInx = 0;
while (aInx < adjs.Count && visited[adjs[aInx]])
{
if (inStack[adjs[aInx]])
{
return(false);
}
aInx += 1;
}
if (aInx == adjs.Count)
{
inStack[node] = false;
reversePostOrder.Push(stack.Pop());
}
else
{
stack.Push(adjs[aInx]);
}
}
return(true);
}
public DirectedDFS(Digraph digraph, int source)
{
visited = new bool[digraph.NodeCount];
Dfs(digraph, source);
}