;2から n までの検索用リストを作成する。
(defun make-search-lst (n &optional (lst nil))
  (if (= n 1)
    lst
    (make-search-lst (1- n) (cons n lst))))
;numで指定された数の倍数をlstから削除する。
(defun delete-multiple-from-search-lst (num lst)
  (labels
    ((rec (i)
          (if (> (* num i) (car (last lst)))
            lst
            (progn
              (setf lst (delete (* num i) lst))
              (rec (1+ i))))))
    (rec 1)))
;s-lstの中から素数を抽出し返却する。
(defun create-prime-lst (s-lst &optional (p-lst nil))
  (if (and
        (not (null p-lst))
        (< (car (last s-lst)) (* (car (last p-lst)) (car (last p-lst)))))
    (append p-lst s-lst)
    (progn
      (setf p-lst (append p-lst (list (car s-lst))))
      (setf s-lst (delete-multiple-from-search-lst (car (last p-lst)) s-lst))
      (create-prime-lst s-lst p-lst))))
;結果表示関数
(defun print-lst (lst)
  (format t "~a => (" 'lst)
  (labels
    ((rec (lst)
          (if (null lst)
            (format t ")~%")
            (progn
              (format t "~d " (car lst))
              (rec (cdr lst))))))
    (rec lst)))
(print-lst (create-prime-lst (make-search-lst 100)))

;2から n までの検索用リストを作成する。 (defun make-search-lst (n &optional (lst nil)) (if (= n 1) lst (make-search-lst (1- n) (cons n lst)))) ;numで指定された数の倍数をlstから削除する。 (defun delete-multiple-from-search-lst (num lst) (labels ((rec (i) (if (> (* num i) (car (last lst))) lst (progn (setf lst (delete (* num i) lst)) (rec (1+ i)))))) (rec 1))) ;s-lstの中から素数を抽出し返却する。 (defun create-prime-lst (s-lst &optional (p-lst nil)) (if (and (not (null p-lst)) (< (car (last s-lst)) (* (car (last p-lst)) (car (last p-lst))))) (append p-lst s-lst) (progn (setf p-lst (append p-lst (list (car s-lst)))) (setf s-lst (delete-multiple-from-search-lst (car (last p-lst)) s-lst)) (create-prime-lst s-lst p-lst)))) ;結果表示関数 (defun print-lst (lst) (format t "~a => (" 'lst) (labels ((rec (lst) (if (null lst) (format t ")~%") (progn (format t "~d " (car lst)) (rec (cdr lst)))))) (rec lst))) (print-lst (create-prime-lst (make-search-lst 100)))