ホーム - Project Euler

Problem 9¶

#!r6rs
#!chezscheme

(import (chezscheme))

(define answer-9
  (let loop1 ([a 1])
    (if (< 333 a)
      (error "answer-9" "answer-9 was not found!")
      (let loop2 ([b a])
        (if (< 499 b)
          (loop1 (add1 a))
          (let ([c (- 1000 a b)])
            (if (= (+ (expt a 2)
                      (expt b 2))
                   (expt c 2))
              (* a b c)
              (loop2 (add1 b)))))))))

(printf "9: ~D~%" answer-9)