どうかく？orgでCommon Lispプログラムを書いてみた。

http://ja.doukaku.org/

http://ja.doukaku.org/8/

 1 (defun center (str len &optional (padchar #\ ))
 2   "If LEN is greater than the length of STR, returns a new String
 3    of length LEN with STR centered and padded with PADCHAR;
 4    otherwise, returns STR."
 5   (let ((pad (make-string (/ (- len (length str)) 2) :initial-element padchar)))
 6     (format nil "~a~a~a" pad str pad)))
 7
 8 (defun stars (n)
 9   (- (* 2 n) 1))
10
11 (defun pyramid (n)
12   (loop for i from 1 to n do
13        (format t "~a~%" (center (make-string (stars i) :initial-element #\*)
14                                 (stars n)))))

http://ja.doukaku.org/6/

1 (require 'cl-ppcre)
2 (defun including-tax (string)
3   (cl-ppcre:regex-replace-all
4    "\\d+" string
5    (lambda (num) (format nil "~a" (floor (* (parse-integer num) 1.05))))
6    :simple-calls t))
7
8 ;; CL-USER> (including-tax "ダイコン150円、ハクサイ120円、ジャガイモ30円")
9 ;; "ダイコン157円、ハクサイ125円、ジャガイモ31円"

http://ja.doukaku.org/4/

(defun lot (n m)
  (let ((lot (loop for i from 1 to n collect i)))
    (loop repeat m collect
         (let ((x (nth (random (length lot)) lot)))
           (setf lot (delete x lot))
           x))))
;; (lot 6 3)
;; (lot 9 4)
;; (lot 9999 4)

(defun test-lot (lotfunc n m)
  (loop repeat 100 always
       (let ((result (funcall lotfunc n m)))
         (and (= (length result) m)
              (uniquep result)))))

(defun uniquep (list)
  (loop for elt in list always (= 1 (count elt list))))


;; (uniquep '(1 3 1))
;; (uniquep '(1 2 3))

;; (test-lot #'lot 9 4)
;; (test-lot #'lot 100 4)

http://ja.doukaku.org/9/

(defun %rational->decimal-calc (rat)
  (let ((a (numerator rat))
        (b (denominator rat))
        ret mods)
    (loop
       do
         (setf a (* 10 a))
         (push (floor (/ a b)) ret)
         (setf a (mod a b))
       until
         (or (zerop a) (member a mods))
       do
         (push a mods)
       finally
         (setf ret (nreverse ret)))
    (if (zerop a)
        ret
        (nconc (insert ret (position (floor (/ (* 10 a) b)) ret :from-end t) "{") '("}")))))

;; insertってこれでいいのかな？
;; integer / integer -> integer な割り算は (floor (/ a b)) 以外に書けるのかな？
(defun insert (list n newelt)
  `(,@(butlast list (- (length list) n)) ,newelt ,@(nthcdr n list)))

(defun rational->decimal (rat)
  (multiple-value-bind (int frac) (truncate rat)
    (format nil "~a.~{~a~}" int (%rational->decimal-calc frac))))
;; (rational->decimal 3/14)
;; (rational->decimal 17/14)
;; (rational->decimal 1/4)

CL-USER> (rational->decimal 3/14)
"0.2{142857}"
CL-USER> (rational->decimal 1/4)
"0.25"
CL-USER> (rational->decimal 17/14)
"1.2{142857}"

ブラウザの操作ミスでダブルで投稿されてしまった。問い合わせようにも「フィードバック」から書き込もうにも500エラーorz
メールアドレスが書いてないから伝えられないよ。