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From: "Chad R. Meiners" <crmeiners@hotmail.com>
Subject: Re: Ada Components - GRACE Lists (Sorting them)
Date: Tue, 26 Feb 2002 06:52:36 -0500
Date: 2002-02-26T06:52:36-05:00	[thread overview]
Message-ID: <a5fs6c$2cir$1@msunews.cl.msu.edu> (raw)
In-Reply-To: 3C76EE71.40506@telepath.com

I remembering that there was a discussion about using quicksort for these
list components.  There was naturally concern about the O(n^2) worst case
performance.  If people are still worried about this issue, I have a
solution that guarantees that quicksort worst case is O(n*log n).  Before
any of you spill your coffee ;-) there is a hefty constant involved that
makes this modified quicksort slower on average than heapsort (maybe
mergesort sort also but it doesn't take more space that mergesort).  Anyway
the idea is to choose the median of each list (sublist) in linear time.
There happens to be a 'well known algorithm' for this.  The only drawback is
a hit on the constant.  I figure it might not be too bad of a price to pay,
though.

Comments?

-CRM





  parent reply	other threads:[~2002-02-26 11:52 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-02-11 15:47 Ada Components - GRACE Lists Marin David Condic
2002-02-12  2:52 ` Pat Rogers
2002-02-12  4:33   ` Eric Merritt
2002-02-12 15:30     ` Pat Rogers
2002-02-12 18:00   ` Marin David Condic
2002-02-13  4:17     ` Eric Merritt
2002-02-13 15:39     ` Pat Rogers
2002-02-14  1:31     ` Jeffrey Carter
2002-02-14 14:27       ` Marin David Condic
2002-02-14  0:32 ` Nick Roberts
2002-02-23  1:26 ` Ted Dennison
2002-02-23 16:41   ` Nick Roberts
2002-02-25 15:42     ` Ted Dennison
2002-02-26  1:05       ` Nick Roberts
2002-02-23 17:07   ` Richard Riehle
2002-02-25 13:04     ` Ted Dennison
2002-02-25 13:38   ` Marin David Condic
2002-02-26  0:57   ` Matthew Heaney
2002-02-26 11:52   ` Chad R. Meiners [this message]
2002-02-26 15:02     ` Ada Components - GRACE Lists (Sorting them) Thomas Wolf
2002-02-26 16:59     ` Ted Dennison
2002-02-26 17:20       ` Darren New
2002-02-26 21:46         ` Ted Dennison
2002-03-02  0:09       ` Matthew Heaney
2002-03-05 19:55 ` gnat-3.14p, libaddr2line and IRIX 6.5 Dirk Baerts
2002-03-05 22:04   ` David C. Hoos
2002-03-06 16:44     ` Stephen Leake
2002-03-06 19:55       ` Dirk Baerts
     [not found]   ` <055101c1c491$c5002e70$453ab4d8@sy.com>
2002-03-06 19:12     ` gnat-3.14p, libaddr2line and IRIX 6.5 : solved ! Dirk Baerts
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