Strongly connected components.
Functor providing functions to compute strongly connected components of a graph.
scc g
computes the strongly connected components of g
.
The result is a pair (n,f)
where n
is the number of
components. Components are numbered from 0
to n-1
, and
f
is a function mapping each vertex to its component
number. In particular, f u = f v
if and only if u
and
v
are in the same component. Another property of the
numbering is that components are numbered in a topological
order: if there is an arc from u
to v
, then f u >= f u
Not tail-recursive. Complexity: O(V+E) The function returned has complexity O(1)