Topic: Name the process :: Game 1

[CAB]

ElpanovEvgeniy
I think you got it.
You started with a hard one. I tried for about 15 minutes but no easy solution.
Perhaps you can post your solution.

[ElpanovEvgeniy]

ElpanovEvgeniy
I think you got it.
You started with a hard one. I tried for about 15 minutes but no easy solution.
Perhaps you can post your solution.

Version 1

Code: [Select]

(defun rec-min (lst mi f)
  ;(rec-min (cdr lst) (car lst) f)
  (cond
    ((not lst) mi)
    (((eval f) (car lst) mi)
     (rec-min (cdr lst) (car lst) f)
    )
    (t (rec-min (cdr lst) mi f))
  ) ;_  cond
) ;_  defun
(defun rec-remove-singl (i lst)
  ;(rec-remove-singl (cadr lst) lst)
  (if lst
    (if (equal i (car lst))
      (cdr lst)
      (cons (car lst) (rec-remove-singl i (cdr lst)))
    ) ;_  if
  ) ;_  if
) ;_  defun
(defun rec-sort-min (lst f)
  ;(rec-sort-min lst)
  (if lst
    ((lambda (x)
       (cons
         x
         (rec-sort-min
           (rec-remove-singl
             x
             lst
           )
           f
         )
       )
     ) ;_  lambda
      (rec-min (cdr lst) (car lst) f)
    )
  ) ;_  if
) ;_  defun

  ; Check:
(setq lst '(7 3 4 6 9 6 7 2 5 3 2 3 6 4 6 3 1)
      f   (function <)
) ;_  setq
(rec-sort-min lst f)
Version 2

Code: [Select]

(defun rec-min-max (lst mi ma f)
  (cond
    ((not lst) (list mi ma))
    (((eval f) (car lst) mi)
     (rec-min-max (cdr lst) (car lst) ma f)
    )
    (((eval f) ma (car lst))
     (rec-min-max (cdr lst) mi (car lst) f)
    )
    (t (rec-min-max (cdr lst) mi ma f))
  ) ;_  cond
) ;_  defun
(defun rec-remove-singl (i lst)
  (if lst
    (if (equal i (car lst))
      (cdr lst)
      (cons (car lst) (rec-remove-singl i (cdr lst)))
    ) ;_  if
  ) ;_  if
) ;_  defun
(defun rec-sort-min-max (lst f)
  (cond
    ((not lst) nil)
    ((not(cdr lst)) lst)
    (t
     ((lambda (x)
        (cons
          (car x)
          (append
            (rec-sort-min-max
              (rec-remove-singl
                (car x)
                (rec-remove-singl
                  (cadr x)
                  lst
                ) ;_  rec-remove-singl
              ) ;_  rec-remove-singl
              f
            ) ;_  rec-sort-lists
            (cdr x)
          ) ;_  append
        ) ;_  cons
      ) ;_  lambda
       (rec-min-max (cdr lst) (car lst) (car lst) f)
     )
    )
  ) ;_  cond
) ;_  defun

  ; Check:
(setq lst '(7 3 4 6 9 6 7 2 5 3 2 3 6 4 6 3 1)
      f   (function <)
) ;_  setq
(rec-sort-min-max lst f)

Version 3

Code: [Select]

(defun rec-quicksort-2 (lst lst1 lst2 test f)
  (cond
    ((not lst)
      (list lst1 (list test) lst2)
    )
    (((eval f) (car lst) test)
     (rec-quicksort-2 (cdr lst) (cons (car lst) lst1) lst2 test f)
    )
    (t (rec-quicksort-2 (cdr lst) lst1 (cons (car lst) lst2) test f))
  ) ;_  cond
) ;_  defun

(defun rec-quicksort-1 (lst f)
  (cond
    ((not lst) nil)
    ((not (car lst)) (rec-quicksort-1 (cdr lst) f))
    ((not (cdar lst))
     (cons (caar lst) (rec-quicksort-1 (cdr lst) f))
    )
    ((not (cddar lst))
     (if (apply f (car lst))
       (cons (caar lst) (cons (cadar lst) (rec-quicksort-1 (cdr lst) f)))
       (cons (cadar lst) (cons (caar lst) (rec-quicksort-1 (cdr lst) f)))
     ) ;_  if
    )
    (t
     ((lambda (x)
        (rec-quicksort-1 (cons (car x) (cons (cadr x) (cons (caddr x) (cdr lst)))) f)
      ) ;_  lambda
       (rec-quicksort-2 (cdar lst) nil nil (caar lst) f)
     )
    )
  ) ;_  cond
) ;_  defun

(defun rec-quicksort (lst f)
  (rec-quicksort-1 (list lst) f)
) ;_  defun

  ; Check:
(setq lst '(7 3 4 6 9 6 7 2 5 3 2 3 6 4 6 3 1)
      f   (function <)
) ;_  setq
(rec-quicksort lst f)



[ElpanovEvgeniy]

All this, you can see:

The original (RU):
http://www.autocad.ru/cgi-bin/f1/board.cgi?t=25113OT
Machine translation (EN):
http://babelfish.altavista.com/babelfish/trurl_pagecontent?lp=ru_en&trurl=http%3a%2f%2fwww.autocad.ru%2fcgi-bin%2ff1%2fboard.cgi%3ft%3d25113OT
{Editing = add
see: Lessons 8 - 10}

[CAB]

No wonder I was having trouble figuring it out.
Thanks for the link, I'll do some reading. Just need more time....