用Common Lisp写一个双色球程序

断断续续的看了些Common Lisp的东西，主要是田春冰河翻译的那本《实用Common Lisp编程》，另外网上有人翻译了《ANSI Common Lisp》也有看，另一本《Common Lisp： A Gentle Introduction to Symbolic Computation》。总得写点东西，于是就写了这个双色球的小程序。

(defconstant total-red-ball 33)
(defconstant total-blue-ball 16)

(defun select-red-ball (red-balls double-balls)
  (let (x)
    (setq x (elt red-balls (random (length red-balls))))
    (vector-push x double-balls)
    (delete x red-balls)))

(defun create-double-balls()
  (let ((red-balls (make-array total-red-ball :fill-pointer 0))
	(blue-balls (make-array total-blue-ball :fill-pointer 0))
	(double-balls (make-array 7 :fill-pointer 0)))
    (loop for i from 1 to total-red-ball do (vector-push i red-balls))
    (loop for i from 1 to total-blue-ball do (vector-push i blue-balls))
    (dotimes (n 6)
      (select-red-ball red-balls double-balls))
    (setq double-balls (sort double-balls #'<))
    (vector-push (elt blue-balls (random 16)) double-balls)
    (print double-balls)))
    
(defun gen(n)
  (dotimes (i n)
    (create-double-balls)))

Lisp特殊的语法风格确实与C体系的语言有很大不同，不过如果有编程经验的话，还是比较容易上手，比如函数的传参，传个数组的话，实际上传指针了。定义局部变量的方式比如用LET。