void Dfs(DirectedGraph g, int v)
{
onStack[v] = true;
marked[v] = true;
foreach (var i in g.Adj(v))
{
if (HasCircle())
{
return;
}
else if (!marked[i])
{
edgeTo[i] = v;
}
else if (onStack[i])
{
circle = new Stack <int>();
for (int j = v; j != i; j = edgeTo[j])
{
circle.Push(j);
}
circle.Push(i);
circle.Push(v);
}
}
onStack[v] = false;
}
void Dfs(DirectedGraph g, int v)
{
marked[v] = true;
foreach (var i in g.Adj(v))
{
if (!marked[i])
{
Dfs(g, i);
}
}
}
void Dfs(DirectedGraph g, int v)
{
pre.Enqueue(v);
marked[v] = true;
foreach (var i in g.Adj(v))
{
if (!marked[i])
{
Dfs(g, i);
}
}
post.Enqueue(v);
reversePost.Push(v);
}
