Stack <int> postReverseOrder; // this is used by the Topological Order call
public DepthFirstOrder(Digraph g)
{
isMarked = new bool[g.V()];
for (int i = 0; i < g.V(); i++)
{
if (!isMarked[i])
{
DFS(g, i);
}
}
}
public DirectedCycle(Digraph dg)
{
marked = new bool[dg.V()];
onStack = new bool[dg.V()];
edgeTo = new int[dg.V()];
for (int i = 0; i < dg.V(); i++)
{
if (!marked[i])
{
DFS(dg, i);
}
}
}
public SCC(Digraph g)
{
dg = g;
Digraph gReverse = g.Reverse();//get the reverse of the orinal graph
isMarked = new bool[g.V()];
//we will need do two passes of DFS
//the first pass is to get the post reverse order of the reverse graph
DepthFirstOrder dfs = new DepthFirstOrder(gReverse);
//the reverse order will put the sink vertex of the orginal at the top of the stack returned
IEnumerable <int> postReverse = dfs.PostReverseOrder();
foreach (int v in postReverse)
{
if (!isMarked[v]) //now we remove one sink at a time, and find the SCC component
{ //the number of the SCC is equal to the number of the times we get isMarked[v]==true;
DFS(g, v);
count++;
Console.WriteLine(0);
}
}
}
