Re: puzzle with string permutations [photo]

[Emanuel Berg]

>> (calc-eval "fact(5)") => "120"
>> (calc-eval "fact(10)") => "3628800"
>
> Indeed, however that isn't lispy either ...

(defun faculty (n)
  (if (> n 1)
      (* n (faculty (1- n)))
    1) )
;; (faculty  5) ;       120
;; (faculty 10) ; 3 628 800

(defun string-perms-num (str)
  (faculty (length str) ))
;; (string-perms-num "kudce") ; 120

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