SICPゼミ第27回
練習問題3.53
1,2,4,8,16....
練習問題3.54
(define (mul-streams s1 s2) (stream-map * s1 s2)) (define factorials (cons-stream 1 (mul-streams (stream-cdr integers) factorials)))
練習問題3.55
(define (partial-sums s) (cons-stream (stream-car s) (add-streams (partial-sums s) (stream-cdr s))))
練習問題3.56
(define S (cons-stream 1 (merge (scale-stream integers 2) (merge (scale-stream integers 3) (scale-stream integers 5)))))
by pine
練習問題3.59
a.
(define q-integers (stream-map / ones integers)) (define (integrate-series s) (mul-streams s q-integers))
b.
(define cosine-series (cons-stream 1 (stream-map (lambda (x) (- x)) (integrate-series sine-series)))) (define sine-series (cons-stream 0 (integrate-series cosine-series)))
by dolicas
練習問題3.60
(define (mul-series s1 s2) (cons-stream (* (stream-car s1) (stream-car s2)) (add-streams (scale-stream (stream-cdr s2) (stream-car s1)) (mul-series (stream-cdr s1) s2))))
by dolicas
練習問題3.61
(define (invert-unit-series s) (stream-cons 1 (scale-stream (mul-series (stream-cdr s) (invert-unit-series s)) (- 1))))
by dolicas
練習問題3.62
(define (div-series s1 s2) (let ((inv (/ 1 (stream-car s2)))) (scale-stream (mul-series s1 (invert-unit-series (scale-stream s2 inv))) inv)))