// topological sort
// backwards Adj -> Bdj
public static int[][] TransitiveClosure(Graph g)
{
int[][] closure = new int[g.V][];
for (int v = 0; v < g.V; v++)
{
closure[v] = Bits.BitsArray(g.V);
}
for (int v = 0; v < g.V; v++)
{
Bits.MarkBit(closure[v], v);
for (int i = 0; i < g.Deg(v); i++)
{
int v1 = g.BdjV(v, i);
for (int u = 0; u < g.V; u++)
{
if (Bits.IsMarked(closure[v], u))
{
Bits.MarkBit(closure[v1], u);
}
}
}
}
}