private void DfsVisit(GraphBase g, int u, int p)
{
_marked[u] = true;
foreach (var v in g.Adj(u))
{
if (_hasCycle)
{
break;
}
if (!_marked[v])
{
_parents[v] = u;
DfsVisit(g, v, u);
}
else if (v != p)
{
_cycle = new Stack <int>();
_cycle.Push(v);
while (u != v)
{
_cycle.Push(u);
u = _parents[u];
}
_cycle.Push(v);
_hasCycle = true;
break;
}
}
}
private void DfsVisit(GraphBase g, int u, int p)
{
_vertices[u].Color = Color.Gray;
foreach (var v in g.Adj(u))
{
if (_hasCycle)
{
break;
}
if (_vertices[v].Color != Color.Gray)
{
_vertices[v].Parent = _vertices[u];
DfsVisit(g, v, u);
}
else if (v != p)
{
_cycle = new Stack <int>();
_cycle.Push(v);
while (u != v)
{
_cycle.Push(u);
u = _vertices[u].Parent.Val;
}
_cycle.Push(v);
_hasCycle = true;
break;
}
}
}