[Jprogramming] Permutations

[Linda Alvord]

I knew how to get tree diagrams in earlier versions of J, but wonder how to
get them in J701jhs.

Linda

-----Original Message-----
From: programming-bounces at jsoftware.com
[mailto:programming-bounces at jsoftware.com] On Behalf Of David Mitchell
Sent: Thursday, September 29, 2011 6:24 AM
To: Programming forum
Subject: Re: [Jprogramming] Permutations

I find this helpful to see differences:

    /:~ :/:@": &.>a,b
                      -- ~ --- /:
                -- : -+- /:
          -- @ -+- ":
   -- &. -+- >
   │
--+      -- a
   L------+- ,
          L- b


    /:~:([:/:": )&.>a,b
   -- /:
   │    -- ~:
   │    │          -- [:
--+    │      ----+- /:
   │    +- &. -+   L- ":
   L----+      L- >
        │
        │      -- a
        L------+- ,
               L- b

--
David Mitchell

On 9/29/2011 5:45, Linda Alvord wrote:
> The only difference between the correct and the incorrect result is a
space
> before the second  :  .   Should a space make a difference ever? In the
> correct result I can't understand what it is, what it does and why it does
> it.
>
>     /:~ :/:@":&.>a,b
> ------T-----┐
> │01123│01123│
> L-----+------
>
>
>     /:~:([:/:": )&.>a,b
> 0 1
>
> Since I set out originally to remove "atop", how can I do it?
>
>    /:~ :([: /: ":)&.>a,b
> ------T-----┐
> │10123│32110│
> L-----+------
>
> Hope you can help.  Thanks.  Linda
>
> -----Original Message-----
> From: programming-bounces at jsoftware.com
> [mailto:programming-bounces at jsoftware.com] On Behalf Of Ian Clark
> Sent: Thursday, September 22, 2011 9:13 PM
> To: Programming forum
> Subject: Re: [Jprogramming] Permutations
>
> Off-the-cuff...
>
>     a=: 10123
>     b=: 32110
>     c=: 32100
> -:/ /:~ :/:@":&.>   a,b
> 1
> -:/ /:~ :/:@":&.>   a,c
> 0
>
>
> On Thu, Sep 22, 2011 at 10:41 PM, David Vaughan
> <purpleblues13 at googlemail.com>  wrote:
>> Hi, what is the best (fastest) way to check whether a number is a
> permutation of another number?
>> I've tried listing all permutations of one number and checking whether
the
> other number is in the list of permutations. This seems pretty slow, so I
> was hoping for a faster method.
>>
>> Thanks.
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