Topic: Increment Challenge..

[Andrea]

Hi All,..

for any who are interested to this challenge..
The function must increment Alphabetic value with two (2) parameter...

ex: (AphaIncrement  A B)

A= Start Letter as a string
B= Increment value as integer (this can be also negative value)

So the challenge is this...
(AphaIncrement  "A" 1) = "B"
(AphaIncrement  "D" 3) = "G"
(AphaIncrement  "AAP" 1) = "AAQ"
(AphaIncrement  "BAU" 2) = "BAW"
(AphaIncrement  "A" -1) = "Z"
(AphaIncrement  "FFFC" 2) = "FFFE"

the goal is to have,...
a,b,c,d,e,....z,
aa,ab,ac,ad,ae...az,
ba,bc,bd,be,..bz
ca,cb,cd,ce,...cz,..
etc...

$5 for who can make this....

Get ready !...
this challenge will start NOW !

Good luck ! 

[VovKa]

(AphaIncrement  "A" -1) = "Z"

are you sure about this one?

[Lee Mac]

http://lee-mac.com/columnreference.html#incalpha

[MP]

Should've held out for a sammich.

[Andrea]

(AphaIncrement  "A" -1) = "Z"

are you sure about this one?

You're right....no sense..it must be nil or "A"
+1

[Andrea]

http://lee-mac.com/columnreference.html#incalpha

LEE !!!!!!!!!!!!!!   that's sick !  4 recursive in row !?
you're just amazing..

one thing....your code do not allow negative value..as increment.

[roy_043]

(AphaIncrement  "A" -1) = "Z"

are you sure about this one?

You're right....no sense..it must be nil or "A"
+1

You need a representation for zero. If "A" is the first digit it follows that it represents zero. But this is counterintuitive. And if "A" is zero then "AA" is zero as well.

[VovKa]

You need a representation for zero. If "A" is the first digit it follows that it represents zero. But this is counterintuitive. And if "A" is zero then "AA" is zero as well.

i believe Lee's code is written to deal with MS Excel, so it's got no zero

[VovKa]

i have this to work with custom "numeral" systems based on positional notation
no negative numbers

Code: [Select]

(defun vk_AlphaBet2Dec (ABC AlphaBet / Len)
  (setq Len (strlen AlphaBet))
  (if (/= ABC "")
    (+ (* (expt Len (1- (strlen ABC)))
  (vl-string-position (ascii (substr ABC 1 1)) AlphaBet)
       )
       (vk_AlphaBet2Dec (substr ABC 2) AlphaBet)
    )
    0
  )
)
(defun vk_Dec2AlphaBet (Dec AlphaBet / Len)
  (setq Len (strlen AlphaBet))
  (if (< Dec Len)
    (substr AlphaBet (1+ Dec) 1)
    (strcat (vk_Dec2AlphaBet (/ Dec Len) AlphaBet)
    (substr AlphaBet (1+ (rem Dec Len)) 1)
    )
  )
)


Code: [Select]

(vk_Dec2AlphaBet 35 "01")
(vk_Dec2AlphaBet 35 "0123456789")
(vk_Dec2AlphaBet 35 "0123456789ABCDEF")
(vk_Dec2AlphaBet 35 "ABCDEFGHIJKLMNOPQRSTUVWXYZ")
(vk_Dec2AlphaBet 35 "Aa")
(vk_Dec2AlphaBet 35 "theSwamp")


[gile]

Hi,

Quite a long time since I've been here...

You can see the (quite old too) topic.

[Marc'Antonio Alessi]

Code: [Select]

(defun ALE_ZetaStrIncVal (ZetStr IncVal / SttStr SttLen)
  (if (eq "" (setq SttStr (vl-string-right-trim "Z" ZetStr)))
    (strcat (vl-string-translate "Z" "A" ZetStr) "A")
    (strcat
      (substr SttStr 1 (setq SttLen (1- (strlen SttStr))))
      (chr (+ IncVal (vl-string-elt SttStr SttLen)))
      (if (eq ZetStr SttStr)
        ""
        (vl-string-translate "Z" "A" (substr ZetStr (+ 2 SttLen)))
      )
    )
  )
)


Code: [Select]

(ALE_ZetaStrIncVal  "A" 1) "B"
(ALE_ZetaStrIncVal  "D" 3) "G"
(ALE_ZetaStrIncVal  "AAP" 1) "AAQ"
(ALE_ZetaStrIncVal  "BAU" 2) "BAW"
(ALE_ZetaStrIncVal  "A" -1) "@"  <<<<<<<<<<<<<<<<<
(ALE_ZetaStrIncVal  "FFFC" 2) "FFFE"

[Andrea]

this is my quick attempt..
Working with negative value and Upper or lower case

Code: [Select]

(defun AA:setcar (startwith increment / carpref iba_alphabet cval str# startwith2 nextcar newstartwith)
  (setq startwith2 startwith)
  (if (< (ascii (substr startwith 1 1)) 96)
    (setq cval 64)
    (setq cval 96)
  )
  (setq iba_alphabet nil)
  (repeat 26
    (setq iba_alphabet (append iba_alphabet (list (chr (setq cval (1+ cval))))))
  )
  (setq carpref "")
  (if (> (setq str# (strlen startwith2)) 1)
    (progn (setq carpref (substr startwith2 1 (1- str#)))
           (setq startwith2 (substr startwith2 str#))
    )
  )
  (if (not
        (setq nextcar (nth (+ increment (vl-position startwith2 iba_alphabet))
                           iba_alphabet
                      )
        )
      )
    (progn (setq carpref startwith)
           (if (> (setq str# (strlen startwith2)) 1)
             (progn (setq carpref (substr startwith2 1 (1- str#)))
                    (setq startwith2 (substr startwith2 str#))
             )
           )
           (setq nextcar startwith2)
    )
  )
  (setq newstartwith (strcat carpref nextcar))
)

[Andrea]

Well,...you guys are just amazing..
many concept, diffrent thinking remind me how human can be intelligent sometime.
Thank you very much for sharing all these samples and knowledge.

Now,..who is the winner of this 5$ ?   

[Andrea]

Test Made:

Code: [Select]

(ALE_ZetaStrIncVal "aa" -1)   = "a`"   I think it must be "z"  ?


Code: [Select]

(LM:incalpha "a" 1)  = "AH"  ?   lowercase ?


Code: [Select]

(incsuff "aB" 1 7) = work perfectly


Code: [Select]

(aa:setcar "BB" -1)  = "BA"
(aa:setcar "BA" -1) = Error  :)

so,.....GILE is the winner !
Also,..his code allow numeric value and respect CASE sensitive..
nice coding GILE.  merci.

[gile]

Merci Andrea,

This routine has been used as base routine in the "Increment" LISP suite which is the ancestor of the quite popular .NET "Increment" plugin on Exchange Apps.