Finding path between 2 points in Racket

Question

I have following list of connections:

(define routelist
  (list
      (list\'a \'b)
      (list\'a \'c)
      (list\'b \'e)
      (list\'b \'f)
      (list\         


        

Answer 1

Use DFS algorithm will be ok.

(define (mainpath routelist start end)
  (letrec ([next-nodes (λ (node)
                        (for/list ([al routelist]
                                   #:when (eq? node (first al)))
                                  (second al)))]
           [path (λ (node vlist)
                   (let ([new-list (cons node vlist)])
                     (when (eq? node end)
                       (println (reverse new-list)))
                     (for ([next (next-nodes node)]
                           #:unless (memq next vlist))
                          (path next new-list))))])
    (path start '())))