## quick sort

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### quick sort

hello every body ,
I tried to sort a list by using the quick sort algorithm
I put this code but I can not get the result

(defun qsort (L)
(if (null L)
nil
(append
(qsort (list< (first L) (rest L)) )
(cons (first L) nil)
(qsort (list>= (first L) (rest L)) )
)
)
)

would some one help me please with this code or if there is another code to do that
omarasl

Posts: 12
Joined: Sun Nov 25, 2012 6:19 am

### Re: quick sort

And how does the implementation of list< and list>= functions look?
cl-2dsyntax is my attempt to create a Python-like reader. My mirror of CLHS (and the dark themed version). Temporary mirrors of aferomentioned: CLHS and a dark version.

Goheeca

Posts: 271
Joined: Thu May 10, 2012 12:54 pm

### Re: quick sort

I haven't changed your code, just put it in code-tags. I tested it and it works.
Code: Select all
`(defun qsort (L)   (if (null L)       nil      (append                  (qsort (list< (first L) (rest L)))                  (cons (first L) nil)                  (qsort (list>= (first L) (rest L))))))`

You need to define list< and list>= as well since it's a large part that's obviously missing but if they return lists lower and higher than the first element you have (numeric) quick sort
I'm the author of two useless languages that uses BF as target machine.
Currently I'm planning a Scheme compiler :p
sylwester

Posts: 130
Joined: Mon Jul 11, 2011 2:53 pm