K2.scm

K2.scm

;Georgi Ivanov Hristozov 80430

(define g '(
            (1 2 3)
            (2 3 6)
            (3 4 5)
            (4 1 2 5)
            (5 3)
            (6 2)))

;Vrushta vsichki susedi na node
(define (getnbrs node g)
  (let
      ((found (assq node g)))
    (if found
        (cdr found)
        '())))

;Vrushta vsichki putishta, zapochvashti ot node
;DFS
(define (getAllFrom node g way)
  (if (or (null? node) (memq node way))
      ()
      (let*
          ((nbrs (getnbrs node g))
           (nbrs-filtered (filter (lambda (node) (not (memq node way))) nbrs))
           (nextways (apply append (map (lambda (newnode) (getAllFrom newnode g (cons node way))) nbrs-filtered)))
           )
        (if (null? nbrs-filtered)
            (list (cons node way))
            nextways))))

(define (paths-through node g)
  (let*
      ((all-ways (map reverse (apply append (map (lambda (node) (getAllFrom node g ())) (map car g)))))
       (all-ways-filtered (filter (lambda (way) (memq node way)) all-ways))
       )
    all-ways-filtered))

;testove
(paths-through 4 g)