vx-scheme/testcases/pi.scm

28 lines
696 B
Scheme

(define (pi n . args)
(let* ((d (car args))
(r (do ((s 1 (* 10 s))
(i d (- i 1)))
((zero? i) s)))
(n (+ (quotient n d) 1))
(m (quotient (* n d 3322) 1000))
(a (make-vector (+ 1 m) 2)))
(vector-set! a m 4)
(do ((j 1 (+ 1 j))
(q 0 0)
(b 2 (remainder q r)))
((> j n))
(do ((k m (- k 1)))
((zero? k))
(set! q (+ q (* (vector-ref a k) r)))
(let ((t (+ 1 (* 2 k))))
(vector-set! a k (remainder q t))
(set! q (* k (quotient q t)))))
(let ((s (number->string (+ b (quotient q r)))))
(do ((l (string-length s) (+ 1 l)))
((>= l d) (display s))
(display #\0)))
(if (zero? (modulo j 10)) (newline) (display #\ )))
(newline)))
(pi 300 5)