Need a function that re-arranges words(!)

[Geoff Canyon]

How many words do you want to handle? You say *any* but the number of 
permutations increases very quickly, so you'd have to come up with a 
different way of solving it if you wanted to handle 100 words, for 
example. If N is the number of words, the number of strings to generate 
is

N!*2^(N-1)

So 2 words have 4 arrangements, 3 words have 24 arrangements (as shown 
below), 4 words have 192 arrangements...10 words have 1,857,945,600 
permutations, etc.

For rearranging the words, a recursive function would work nicely. For 
selectively pulling out the spaces my first guess would be to count 
from 0 to 2^(N-1) -1, convert each number to binary using baseConvert, 
and use the 1s and 0s of the resulting string as a guide to inserting a 
space or not. As it turned out, it was better to count from 2^(N-1) to 
2^N - 1 and then pull the leading "1" in order to get the leading 
zeroes.

This will do the trick, but will quickly choke out on longer strings. 
Try it with "test this code" or "this is a test" or "fuzzy wuzzy was a 
bear" but save your work before attempting "peter piper picked a peck 
of pickled peppers" -- it would produce a string over 200MB in size 
(assuming your system's virtual memory system is up to the task).

local sResultList

on rearrangeWords pString,pWordList
   if the number of words of pWordList is 1 then
     put enumerateSpaces(pString && pWordList) after sResultList
     exit rearrangeWords
   end if
   repeat with i = 1 to the number of words in pWordList
     put pWordList into tWordList
     delete word i of tWordList
     rearrangeWords pString && word i of pWordList,tWordList
   end repeat
end rearrangeWords

function enumerateSpaces pString
   put empty into tReturn
   put the number of words in pString into tWC
   repeat with i = 2^(tWC -1) to 2^(tWC)-1
     put char 2 to -1 of baseConvert(i,10,2) into tBitString
     put 0 into tCounter
     repeat for each word W in pString
       add 1 to tCounter
       if tCounter is tWC then
         put W & cr after tReturn
       else
         if char tCounter of tBitString is 1 then
           put W & space after tReturn
         else
           put W after tReturn
         end if
       end if
     end repeat
   end repeat
   return tReturn
end enumerateSpaces



regards,

Geoff Canyon
gcanyon at inspiredlogic.com

On Nov 24, 2003, at 3:32 PM, valetia at mac.com wrote:

> Hi all,
>
> Help! :) I've been trying to figure this out but it's been a mess, even
> though I think it's probably an easy one.
>
> What I need is rev code that can do this:
>
> Given any phrase, e.g.: "my fat cat"
>
> Spit out all of the following (no need to be in this order):
>
> my fat cat
> my cat fat
> fat my cat
> fat cat my
> cat my fat
> cat fat my
>
> myfat cat
> my fatcat
> myfatcat
>
> mycat fat
> my catfat
> mycatfat
>
> fatmy cat
> fat mycat
> fatmycat
>
> fatcat my
> fat catmy
> fatcatmy
>
> catmy fat
> cat myfat
> catmyfat
>
> catfat my
> cat fatmy
> catfatmy
>
>
> Conditions:
>
> 1. The input phrase can be *any* number of words (not just 3).
>
> 2. Each line of the results must contain all the words within (no 
> missing
> words).
>
> Any takers? Thanks in advance! :)
>
> Valetia
>
>
>
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