roll.lisp

(setf *random-state* (make-random-state t))

(defun dice ()
  (random 2))

(defun roll (n)
  (let ((x 0)
        (count 0))
    (loop while (< x n) do
      (incf count)
      (if (= 1 (dice))
        (incf x)
        (setq x 0)))
    count))

(defvar times 10)

(loop for i from 1 to times do
  (format t "#~A  第 ~A 次：擲出 ~A 次正面~%" i (roll times) times))