;; Scheme code from lecture 3

(define (make-list low hi)
  (if (> low hi)
      '()
      (cons low (make-list (+ low 1)  hi))))

(define big-list (make-list 0 100000))

(define (rev L)
  (tail-rev L '()))

(define (tail-rev L A)
  (cond
    [ (null? L) A ]
    [ else (tail-rev (rest L) (cons (first L) A)) ] ))

(define (my-reverse L)
  (if (null? L)
      '()
      (append (my-reverse (rest L)) (list (first L)))))

(define (my-tail-reverse L)
  (my-t-rev-help L '()))

(define (my-t-rev-help L ans)
  (if (null? L)
      ans
      (my-t-rev-help (rest L) (cons (first L) ans))))


(define (smush L)
  (foldr append '() L))

(define (addk k L)
  (map (lambda (elem) (+ k elem)) L))

(define Amy '(Amy 2 3 41 42 50))
(define Bea '(Bea 3 40 50 51 52))
(define TL1  (list Amy Bea))
(define W1  '(1 3 41 51 52))

(define (matches L1 L2)
  (foldr + 0 (map (lambda (n) (markit n L2)) L1)))

(define (markit elem L)
  (if (member elem L)
      1
      0))

(define (lotto TL W)
  (foldr (lambda (s1 s2) 
           (if (> (second s1) (second s2))
               s1
               s2))
         '("chrsitine" 0)
         (score-em TL W)))

(define (score-em TL W)
  (map (lambda (L) (score L W)) TL))

(define (score L W)
  (list (first L) (matches (rest L) W)))

(define (drop-more k L)
  (filter (lambda (x) (<= x k)) L))


(define (generate-menu entrees desserts unavail)
  (let ((e (filter (lambda (f) (not (member f unavail))) entrees))
        (d (filter (lambda (f) (not (member f unavail))) desserts)))
    (all-pairs e d)))

(define (one-pair elem L)
  (map (lambda (e) (list elem e)) L))

(define (all-pairs en de)
  (foldr append '() (map (lambda (e) (one-pair e de)) en)))

(define entrees (list "steak" "pasta" "chicken" "turkey"))
(define desserts (list "chocolate mousse" "lemon pie" "cake"))
(define unavailable (list "pasta" "lemon pie"))