Re: Pattern Matching in Lists
- To: mathgroup at smc.vnet.net
- Subject: [mg35607] Re: Pattern Matching in Lists
- From: "Allan Hayes" <hay at haystack.demon.co.uk>
- Date: Mon, 22 Jul 2002 02:11:09 -0400 (EDT)
- References: <ah8ojs$au6$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Adding Andrzej's idea using a single rotation with correction to Carl's latest gives a further speed up: w=Table[Random[Integer],{1000000}]; (Tr[#]-Tr[BitAnd[# ,Drop[w,1]]])&[Drop[w,-1] ]//Timing {2.36 Second,249981} (Tr[w]-Tr[BitAnd[w ,RotateLeft[w]]])+ If[w[[1]]==0&&w[[-1]]==1,-1,0]//Timing {1.43 Second,249981} -- Allan --------------------- Allan Hayes Mathematica Training and Consulting Leicester UK www.haystack.demon.co.uk hay at haystack.demon.co.uk Voice: +44 (0)116 271 4198 Fax: +44 (0)870 164 0565