; Second Homework Set
; CSc 335
; Spring 2021
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; This is a long problem set – you will want to set aside some hours.
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; I am posting this somewhat in advance of discussing
; the relevant material in lecture. As I have said, it is a good idea
; to start thinking about the problems right away: you’ll be primed to
; pick up on information which will help you solve them.
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; Proofs must be given for all programs
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; 1. Abelson and Sussman, Problems 1.11 and 1.12
; 2. Write iterative and recursive scheme functions to return the sum of the digits within
; a non-negative integer. For example, (sum-of-digits 345) is 12.
; 3. Write iterative and recursive scheme programs to test whether the digits in a non-negative
; integer are in increasing order. For example, the digits of 12348 are in increasing order, while
; those of 12343 are not.
; You may find the built-in functions quotient, remainder, truncate, zero? — and perhaps others —
; helpful as you design your solutions for problems 2 and 3. Have a look at the Scheme
; manual.
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