1 665c255d 2023-08-04 jrmu ;; Use this notation to write a procedure same-parity that takes one or more integers and returns a list of all the arguments that have the same even-odd parity as the first argument. For example,
 2 665c255d 2023-08-04 jrmu 
 3 665c255d 2023-08-04 jrmu ;; (define (same-parity parity . integers)
 4 665c255d 2023-08-04 jrmu ;;   (let ((rem (remainder parity 2)))
 5 665c255d 2023-08-04 jrmu ;;     (define (par ints)
 6 665c255d 2023-08-04 jrmu ;;       (cond ((null? ints) '())
 7 665c255d 2023-08-04 jrmu ;; 	    ((= (remainder (car ints) 2) rem) 
 8 665c255d 2023-08-04 jrmu ;; 	     (cons (car ints)
 9 665c255d 2023-08-04 jrmu ;; 		   (par (cdr ints))))
10 665c255d 2023-08-04 jrmu ;; 	    (else (par (cdr ints))))))
11 665c255d 2023-08-04 jrmu ;;   (cons parity (par integers)))
12 665c255d 2023-08-04 jrmu 
13 665c255d 2023-08-04 jrmu ;; par seems not to be in scope in the call at the end
14 665c255d 2023-08-04 jrmu 
15 665c255d 2023-08-04 jrmu 
16 665c255d 2023-08-04 jrmu (define (same-parity parity . integers)
17 665c255d 2023-08-04 jrmu   (let ((rem (remainder parity 2)))
18 665c255d 2023-08-04 jrmu     (define (par ints)
19 665c255d 2023-08-04 jrmu       (cond ((null? ints) '())
20 665c255d 2023-08-04 jrmu 	    ((= (remainder (car ints) 2) rem) 
21 665c255d 2023-08-04 jrmu 	     (cons (car ints)
22 665c255d 2023-08-04 jrmu 		   (par (cdr ints))))
23 665c255d 2023-08-04 jrmu 	    (else (par (cdr ints)))))
24 665c255d 2023-08-04 jrmu     (cons parity (par integers))))
25 665c255d 2023-08-04 jrmu 
26 665c255d 2023-08-04 jrmu 
27 665c255d 2023-08-04 jrmu (define (test-case actual expected)
28 665c255d 2023-08-04 jrmu   (load-option 'format)
29 665c255d 2023-08-04 jrmu   (newline)
30 665c255d 2023-08-04 jrmu   (format #t "Actual: ~A Expected: ~A" actual expected))
31 665c255d 2023-08-04 jrmu 
32 665c255d 2023-08-04 jrmu (test-case (same-parity 1 2 3 4 5 6 7) '(1 3 5 7))
33 665c255d 2023-08-04 jrmu (test-case (same-parity 2 3 4 5 6 7) '(2 4 6))