5.4.4. Running the Evaluator
Exercise 5.26

Exploration of the tail-recursive property of the evaluator

Use the monitored stack to explore the tail-recursive property of the evaluator (section 5.4.2). Start the evaluator and define the iterative factorial procedure from section 1.2.1:

(define (factorial n)
  (define (iter product counter)
    (if (> counter n)
        (iter (* counter product)
              (+ counter 1))))
  (iter 1 1))

Run the procedure with some small values of n. Record the maximum stack depth and the number of pushes required to compute n! for each of these values.

a. You will find that the maximum depth required to evaluate n! is independent of n. What is that depth?

b. Determine from your data a formula in terms of n for the total number of push operations used in evaluating n! for any n ≥ 1. Note that the number of operations used is a linear function of n and is thus determined by two constants.

Nobody's finished this exercise yet. You'll be the first!

There are no comments yet.

Authentication required

You must log in to post a comment.