摘要： 连分数是指形式如$f=\frac{N_1}{D_1+\frac{N_2}{D_2+\frac{N_3}{D3+\cdots}}}$给定的参数是2个procedure，用来返回$N_i$和$D_i$(define (cont-frac-iter n d k) (define (cont-frac-iter-in s n d k) (define new-s (/ (n k) (+ (d k) s))) (if (= k 1) new-s (cont-frac-iter-in new-s n d (- k 1)))) (cont-frac-iter-in 0 n d k))使用的思想是迭代 阅读全文

摘要： 开始读点函数式语言的书，当前主要是SICP。主要的公式是(x)^{1/3}=\frac{x/y^2+2y}，写成迭代的过程为(define (cube-inverse x) (define (good-enough? guess) (< (abs (- (/ (* guess guess guess) x) 1)) 0.0001)) (define (improve guess) (/ (+ (/ x (* guess guess)) (* guess 2)) 3)) (define (cube-inverse-iter guess) (if (good-enough? guess) g 阅读全文