求from到to之间所有勾股数

gg.scm

(use-modules (srfi srfi-1) (ice-9 control))
(define (either . args) (shift k (for-each k args)))
(define (sq x) (* x x))
(define (choice from to) 
  (reset (let ((ll (iota to from))) 
           (let ((x (apply either ll))(y (apply either ll))(z (apply either ll))) 
             (if (= (sq z) (+ (sq x) (sq y))) 
                 (format #t "~a^2 + ~a^2 = ~a^2~%" x y z))))))

(choice 1 5)
==>
3^2 + 4^2 = 5^2
4^2 + 3^2 = 5^2

try 1~100 ?