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Re: Re: faster sublist checking

  • To: mathgroup at smc.vnet.net
  • Subject: [mg48917] Re: [mg48894] Re: faster sublist checking
  • From: DrBob <drbob at bigfoot.com>
  • Date: Wed, 23 Jun 2004 02:51:17 -0400 (EDT)
  • References: <200406220931.FAA10282@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

>> sublistQ[x_List, y_List] := Intersection[x, y] != {}

That CLEARLY doesn't test whether one list is a sublist of the other.

Bobby

On Tue, 22 Jun 2004 05:31:51 -0400 (EDT), Bill Rowe <readnewsciv at earthlink.net> wrote:

> On 6/21/04 at 3:49 AM, jmyers6761 at aol.com (JMyers6761) wrote:
>
>> Why is this?
>
>> A = {3, 5}; B = {1, 2, 3, 4, 5, 6, 7};
>
>> Intersection[B, A] == Sort[A]
>> True
>
>> but
>
>> SublistQ[B_List, A_List] := Intersection[B, A] == Sort[A];
>>
>> SublistQ[B, A]
>> False
>
> That isn't the result I get
>
> In[1]:=
> $Version
>
> Out[1]=
> 5.0 for Mac OS X (June 10, 2003)
>
> In[2]:=
> A={3,5};B={1,2,3,4,5,6,7};
>
> In[3]:=
> Intersection[B, A] == Sort[A]
>
> Out[3]=
> True
>
> In[4]:=
> SublistQ[B_List, A_List] := Intersection[B, A] ==
>     Sort[A];
>
> In[5]:=
> SublistQ[B,A]
>
> Out[5]=
> True
>
> A couple comment on your function SublistQ. It isn't necessary to use sort since
>
> In[6]:=
> sublistQ[x_List, y_List] := Intersection[x, y] != {}
>
> In[7]:=
> sublistQ[A,B]
>
> Out[7]=
> True
>
> --
> To reply via email subtract one hundred and four
>
>



-- 
DrBob at bigfoot.com
www.eclecticdreams.net/index.html


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