;; Shows a maze with a path connecting two given cells
(define (show-path m p1 p2)
  (match-define (maze N M tbl) m)
  (define route (find-path m p1 p2))
  (for ([i N]) (display "+---"))
  (displayln "+")
  (for ([j M])
    (display "|")
    (for ([i (- N 0)])
      (if (member (list i j) route)
          (display " *")
          (display "  "))
      (if (connected? tbl (list i j) (list (+ 1 i) j))
          (display "  ")
          (display " |")))
    (newline)
    (for ([i N])
      (if (connected? tbl (list i j) (list i (+ j 1)))
          (display "+   ")
          (display "+---")))
    (displayln "+"))
  (newline))