1 665c255d 2023-08-04 jrmu (define (fib n)
 2 665c255d 2023-08-04 jrmu   (cond ((= n 0) 0)
 3 665c255d 2023-08-04 jrmu 	((= n 1) 1)
 4 665c255d 2023-08-04 jrmu 	(else (+ (fib (- n 1))
 5 665c255d 2023-08-04 jrmu 		 (fib (- n 2))))))
 6 665c255d 2023-08-04 jrmu 
 7 665c255d 2023-08-04 jrmu (define (fib n)
 8 665c255d 2023-08-04 jrmu   (fib-iter 1 0 n))
 9 665c255d 2023-08-04 jrmu (define (fib-iter a b count)
10 665c255d 2023-08-04 jrmu   (if (= count 0)
11 665c255d 2023-08-04 jrmu       b
12 665c255d 2023-08-04 jrmu       (fib-iter (+ a b) a (- count 1))))
13 665c255d 2023-08-04 jrmu 
14 665c255d 2023-08-04 jrmu (define (count-change cents coins)
15 665c255d 2023-08-04 jrmu   (cond ((= coins 0) 0)
16 665c255d 2023-08-04 jrmu 	((< cents 0) 0)
17 665c255d 2023-08-04 jrmu 	((= cents 0) 1)
18 665c255d 2023-08-04 jrmu 	(else (+ (count-change cents (- coins 1))
19 665c255d 2023-08-04 jrmu 		 (count-change (- cents (largest-coin-value coins)) coins)))))
20 665c255d 2023-08-04 jrmu 
21 665c255d 2023-08-04 jrmu (define (largest-coin-value coins)
22 665c255d 2023-08-04 jrmu   (cond ((= coins 5) 50)
23 665c255d 2023-08-04 jrmu 	((= coins 4) 25)
24 665c255d 2023-08-04 jrmu 	((= coins 3) 10)
25 665c255d 2023-08-04 jrmu 	((= coins 2) 5)
26 665c255d 2023-08-04 jrmu 	((= coins 1) 1)))
27 665c255d 2023-08-04 jrmu 
28 665c255d 2023-08-04 jrmu (count-change 0 0)
29 665c255d 2023-08-04 jrmu ;; 0
30 665c255d 2023-08-04 jrmu (count-change 1 0)
31 665c255d 2023-08-04 jrmu ;; 0
32 665c255d 2023-08-04 jrmu (count-change 0 1)
33 665c255d 2023-08-04 jrmu ;; 1
34 665c255d 2023-08-04 jrmu (count-change 1 1)
35 665c255d 2023-08-04 jrmu ;; 1
36 665c255d 2023-08-04 jrmu (count-change 2 1)
37 665c255d 2023-08-04 jrmu ;; 1
38 665c255d 2023-08-04 jrmu (count-change 2 2)
39 665c255d 2023-08-04 jrmu ;; 1
40 665c255d 2023-08-04 jrmu (count-change 100 5)
41 665c255d 2023-08-04 jrmu 
42 665c255d 2023-08-04 jrmu (define (count-change amount)
43 665c255d 2023-08-04 jrmu   (cc amount 5))
44 665c255d 2023-08-04 jrmu (define (cc amount kinds-of-coins)
45 665c255d 2023-08-04 jrmu   (cond ((= amount 0) 1)
46 665c255d 2023-08-04 jrmu 	((or (< amount 0) (= kinds-of-coins 0)) 0)
47 665c255d 2023-08-04 jrmu 	(else (+ (cc amount
48 665c255d 2023-08-04 jrmu 		     (- kinds-of-coins 1))
49 665c255d 2023-08-04 jrmu 		 (cc (- amount
50 665c255d 2023-08-04 jrmu 			(first-denomination kinds-of-coins))
51 665c255d 2023-08-04 jrmu 		     kinds-of-coins)))))
52 665c255d 2023-08-04 jrmu (define (first-denomination kinds-of-coins)
53 665c255d 2023-08-04 jrmu   (cond ((= kinds-of-coins 1) 1)
54 665c255d 2023-08-04 jrmu 	((= kinds-of-coins 2) 5)
55 665c255d 2023-08-04 jrmu 	((= kinds-of-coins 3) 10)
56 665c255d 2023-08-04 jrmu 	((= kinds-of-coins 4) 25)
57 665c255d 2023-08-04 jrmu 	((= kinds-of-coins 5) 50)))