Re: number of switches
- To: mathgroup at smc.vnet.net
- Subject: [mg47538] Re: number of switches
- From: Jon Harrop <jdh30 at cam.ac.uk>
- Date: Thu, 15 Apr 2004 03:40:40 -0400 (EDT)
- Organization: University of Cambridge
- References: <c5j6vd$qqo$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
fake wrote:
> Consider the lists {1,1,0,1} and {1,1,0,0},{1,0,1,0,1}.
> The first sequence (1101) switches 2 times (#2digit~#3digit,
> #3digit~#4digit}, the second (1100) 1 time, the third 10101 4 times.
>
> I have the following problem.
> Consider a list of binary digits. Which is the easiest way to count the
> number of switches of the list (using Mathematica commands)?
Does this do it?
f[{}] := 0
f[l_] := Length@Split@l - 1
I get:
In := f[{1,1,0,1}]
Out := 2
In := f[{1,1,0,0}]
Out := 1
In := f[{1,0,1,0,1}]
Out := 4
As well as f[{}]=0. :)
Cheers,
Jon.