;; The first three lines of this file were inserted by DrScheme. They record metadata
;; about the language level of this file in a form that our tools can easily process.
#reader(lib "htdp-advanced-reader.ss" "lang")((modname |29.3|) (read-case-sensitive #t) (teachpacks ((lib "draw.ss" "teachpack" "htdp") (lib "arrow.ss" "teachpack" "htdp") (lib "gui.ss" "teachpack" "htdp"))) (htdp-settings #(#t constructor repeating-decimal #t #t none #f ((lib "draw.ss" "teachpack" "htdp") (lib "arrow.ss" "teachpack" "htdp") (lib "gui.ss" "teachpack" "htdp")))))
(define (find-route1 ori dest G)
  (local ((define (find-route ori dest G)
            (cond
              [(symbol=? ori dest) (list ori)]
              [else (local ((define possible-route (find-route/list (neighbors ori G) dest G)))
                      (cond
                        [(boolean? possible-route) false]
                        [else (cons ori possible-route)]))]))
          (define (find-route/list lo-ori dest G)
            (cond
              [(empty? lo-ori) false]
              [else (local ((define possible-route (find-route (first lo-ori) dest G)))
                      (cond [(boolean? possible-route) (find-route/list (rest lo-ori) dest G)]
                            [else possible-route]))]))
          (define (neighbors anode G)
            (first (rest (assf (lambda (x) (equal? anode x)) G)))))
    find-route ori dest G))

(define (neighbors anode agraph)
  (vector-ref agraph anode)) 


(define G (vector '(1 4)
                  '(4 5)
                  '(3)
                  empty
                  '(2 5)
                  '(3 6)
                  empty))

;find-route : node node graph -> (listof nodes)
;Find a route from ori to dest given G and return the route as a (listof nodes).

(define (find-route ori dest G)
  (cond
    [(= ori dest) (list ori)]
    [else (local ((define possible-route (find-route/list (neighbors ori G) dest G)))
            (cond [(boolean? possible-route) false]
                  [else (cons ori possible-route)]))]))

;find-route/list : (listof nodes) node graph -> (listof nodes)
;Find a route from lo-ori (listof nodes) to dest given G and return the route as a (listof nodes).

(define (find-route/list lo-ori dest G)
  (cond
    [(empty? lo-ori) false]
    [else (local ((define possible-route (find-route (first lo-ori) dest G)))
            (cond
              [(boolean? possible-route) (find-route/list (rest lo-ori) dest G)]
              [else possible-route]))]))