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Re: Word permutations - frustrated by lists.

  • To: mathgroup at smc.vnet.net
  • Subject: [mg71703] Re: Word permutations - frustrated by lists.
  • From: Bill Rowe <readnewsciv at sbcglobal.net>
  • Date: Mon, 27 Nov 2006 04:04:13 -0500 (EST)

On 11/26/06 at 5:49 AM, wookiz at hotmail.com (wooks) wrote:

>I seem to have a general problem with results that look right but
>for embedded lists. Here is an example of my problem. This is
>supposed to be a algorithm to generate all permutations of a string.
>T

>Clear[arrangements]
>arrangements[str_String /; StringLength[str] == 1] := {str};
>arrangements[str_String] := (Prepend[arrangements[StringJoin[
>Rest[#]]]], First[#]) & /@
>NestList[RotateRight, Characters[str], StringLength[str] - 1];
>arrangements["dear"]

Here is a one line solution

StringJoin@@@Permutations[Characters@str]

For example

In[4]:=
StringJoin@@@Permutations[Characters@"cat"]

Out[4]=
{cat,cta,act,atc,tca,tac}
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