Determine the separation vertices of a graph.
A graph is said to have a separation vertex v (sometimes called an articulation point) if there exist vertices a and b, where a != b and b != v, and all paths connecting a and b pass through v. A graph which has a separation vertex is called separable, and one which has none is called non-separable.
- graph-separation-vertices:: G -> SEPARATORS * COMPONENTS procedure
Computes the separation vertices of the given graph. Returns a list of separation vertices and a list of graph components that contain a separation vertex.
(require-extension srfi-1) (require-extension digraph) (require-extension graph-separators) (define g (make-digraph 'depgraph "dependency graph")) (define used-by (list (cons 'dax_h 'foo_cpp) (cons 'def_h 'foo_cpp) (cons 'xyz_h 'foo_cpp) (cons 'foo_cpp 'libfoobar_a ) (cons 'foo_cpp 'libzigzag_a) (cons 'libfoobar_a 'app) (cons 'libzigzag_a 'app) )) (define node-list (delete-duplicates (concatenate (list (map car used-by) (map cdr used-by))))) (define node-ids (list-tabulate (length node-list) values)) (for-each (lambda (i n) ((g 'add-node!) i (list #f n))) node-ids node-list) (define node-map (zip node-list node-ids)) (for-each (lambda (e) (match e ((ni . nj) (let ((i (car (alist-ref ni node-map))) (j (car (alist-ref nj node-map)))) ((g 'add-edge!) (list i j (format "~A->~A" ni nj))))) (else (error "invalid edge " e)))) used-by) (graph-separation-vertices g)
Richard Kelsey; ported to Chicken by Ivan Raikov
- Documentation converted to wiki format
- Ported to Chicken 4
- Initial release
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