Exercise 1.31 Higher-order procedures
NaiTuoZhou

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    #| BEGIN (Write your solution here) |#
;recursive
(define (product term a next b)
  (if (> a b)
      1
      (* (term a)
         (product term (next a) next b))))

;iterative
(define (product term a next b)
  (define (iter a result)
    (if (> a b)
        result
        (iter (next a) (* (term a) result))))
  (iter a 1))

;helper
(define (inc x) (+ x 1))
(define (self x) x)

;factorial
(define (factorial x)
  (product self 1 inc x))
#| END |#

    #| BEGIN (Write your solution here) |#
;recursive
(define (product term a next b)
  (if (> a b)
      1
      (* (term a)
         (product term (next a) next b))))

;iterative
(define (product term a next b)
  (define (iter a result)
    (if (> a b)
        result
        (iter (next a) (* (term a) result))))
  (iter a 1))

;helper
(define (inc x) (+ x 1))
(define (self x) x)

;factorial
(define (factorial x)
  (product self 1 inc x))
#| END |#

    #| BEGIN (Write your solution here) |#
;recursive
(define (product term a next b)
  (if (> a b)
      1
      (* (term a)
         (product term (next a) next b))))

;iterative
(define (product term a next b)
  (define (iter a result)
    (if (> a b)
        result
        (iter (next a) (* (term a) result))))
  (iter a 1))

;helper
(define (inc x) (+ x 1))
(define (self x) x)

;factorial
(define (factorial x)
  (product self 1 inc x))
#| END |#

    #| BEGIN (Write your solution here) |#
;recursive
(define (product term a next b)
  (if (> a b)
      1
      (* (term a)
         (product term (next a) next b))))

;iterative
(define (product term a next b)
  (define (iter a result)
    (if (> a b)
        result
        (iter (next a) (* (term a) result))))
  (iter a 1))

;helper
(define (inc x) (+ x 1))
(define (self x) x)

;factorial
(define (factorial x)
  (product self 1 inc x))
#| END |#