lisp-求最大和最小数,if的使用

* (defun maxnum(x y) (if (> x y) x y))
STYLE-WARNING: redefining COMMON-LISP-USER::MAXNUM in DEFUN

MAXNUM
* (maxnum 9 8)

9
* (maxnum 8 9)

9
* (maxnum 112 990)

990

 

使用了progn,progn将其它语句 插入到某语句中 ,即只返回最后一个语句的执行结果

 

* (minofnums *mylist*)

-263
* (maxofnums *mylist*)

126
* 

 下面是代码

 

[deep@deep ~]$ sbcl --load /home/deep/pro/test2.lisp

(defvar *mylist* 
`(23 126 29 -23 23 2 44 -23 0 -263)
)

(defvar *mymax* (car *mylist*))

(defvar *mymin* (car *mylist*))

(defun maxofnums(mlist) 
	(if mlist
		(progn (setf *mymax* (if (> *mymax* (car mlist))	*mymax*	(car mlist)))
		(maxofnums (cdr mlist)))
		*mymax*		
	)
)

(defun minofnums(mlist) 
	(if mlist
		(progn (setf *mymin* (if (< *mymin* (car mlist))	*mymin*	(car mlist)))
		(minofnums (cdr mlist)))
		*mymin*	
	)
)