gistfile1.lisp

(define (get-list l n) 
  (if (= n 0)
      (car l)
      (get-list (cdr l) (- n 1))))

(define (r-gen l n range) 
  (if (= n 1)
    (r-append l range)
    (r-gen (r-append l range) (- n 1) range)))
             
(define (r-append l r)
  (let ((r-num (random r)))
    (if (num-exists? l r-num)
        (r-append l r)
        (append l (list r-num))))) 

(define (num-exists? l f)
  (if (find-num l f (length l))
      #t #f))

(define (find-num l f len)
  (let ((idx (- len 1))) 
    (if (< idx 0)
      #f
      (if (= (get-list l idx) f)
          #t
          (find-num l f idx)))))

(define (swap-list l swp-idx)
  (let ( (left (add-til l 1 swp-idx)) (right (add-til l swp-idx (length l))) (swp (car l)) )
     (append left (list swp) right)
  )
)

(define (add-til l s til) 
  (if (< s til)