;;; armstrong-numbers.el --- armstrong-numbers Exercise (exercism)

;;; Commentary:

;;; Code:
(require 'calc)
(require 'seq)

(defun kj/digits (n)
  (let ((result nil))
    (while (> n 0)
      (push (% n 10) result)
      (setq n (/ n 10)))
    result))

(defun armstrong-p (n)
  (let* ((digits (kj/digits n))
         (ndigits (seq-length digits))
         (fn (lambda (n) (math-pow n ndigits))))
    (eql n (apply '+ (mapcar fn digits)))))

(provide 'armstrong-numbers)
;;; armstrong-numbers.el ends here