Re: offset 1 list indexing

From	cri@tiac.net (Richard Harter)
Newsgroups	comp.lang.c
Subject	Re: offset 1 list indexing
Date	2011-06-17 15:11 +0000
Message-ID	<4dfb6ab6.4169407@text.giganews.com> (permalink)
References	(4 earlier) <rubrum-5D7959.21424215062011@news.albasani.net> <itcscc$9a1$1@dont-email.me> <itct4l$e0g$1@dont-email.me> <ite8cq$sbs$1@dont-email.me> <itfiut$2sc$1@dont-email.me>

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On Fri, 17 Jun 2011 08:56:58 -0400, James Kuyper
<jameskuyper@verizon.net> wrote:

>On 06/16/2011 08:50 PM, Eric Sosman wrote:
>> On 6/16/2011 8:32 AM, James Kuyper wrote:
>>> On 06/16/2011 08:18 AM, Eric Sosman wrote:
>>>> [...]
>>>>       And converting between a one-based index and an N-based
>>>> index *is* simple arithmetic.
>>>
>>> That the transformation can be done, and even that it's easy, doesn't
>>> mean that it's a good idea to perform it. That it's not necessarily a
>>> transformation worth performing, means that it's just plain ridiculous
>>> to misinterpret a refusal to perform it as indicating an inability to
>>> perform it.
>> 
>>      "Heaps" was advanced, and I believe advanced sincerely, as a
>> reason to rely on one-based array indexing.  That's nonsense.
>
>That's too vague, in that it depends upon what you mean by "reason to
>rely on". If it was given a an example of code that's easier to write,
>read, and understand when using one-based indexing, that's entirely
>possible (though I cannot vouch for whether or not it's true), and no
>one has suggested anything stronger than that in this thread. If, on the
>other hand, they suggested that it COULD NOT be implemented with 0-based
>indexing, that would be, as you say, "nonsense".

The code for in-place heaps is (slightly) simpler with one-based
indexing.  In 0-based indexing the children of node n are at nodes
(2*n+1,2*n+2, in 1-based indexing they are at (2*n,2*n+1).  It's not a
big deal but the resulting code is a bit easier to read, write, and
debug.

Thread

offset 1 list indexing Michael Press <rubrum@pacbell.net> - 2011-06-14 21:02 -0700
  Re: offset 1 list indexing Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-06-14 21:29 -0700
  Re: offset 1 list indexing Nobody <nobody@nowhere.com> - 2011-06-15 05:58 +0100
  Re: offset 1 list indexing Tim Rentsch <txr@alumni.caltech.edu> - 2011-06-15 02:51 -0700
  Re: offset 1 list indexing jacob navia <jacob@spamsink.net> - 2011-06-15 12:01 +0200
    Re: offset 1 list indexing gwowen <gwowen@gmail.com> - 2011-06-15 03:55 -0700
  Re: offset 1 list indexing Mark Bluemel <mark_bluemel@pobox.com> - 2011-06-15 11:07 +0100
    Re: offset 1 list indexing Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-06-15 07:30 -0700
      Re: offset 1 list indexing Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-06-15 11:19 -0600
        Re: offset 1 list indexing James Kuyper <jameskuyper@verizon.net> - 2011-06-15 22:57 -0400
        Re: offset 1 list indexing Joseph Huber <joseph.huber@NOREPLY.web.de> - 2011-06-16 09:28 +0200
          Re: offset 1 list indexing Angel <angel+news@spamcop.net> - 2011-06-16 15:05 +0000
          Re: offset 1 list indexing jacob navia <jacob@spamsink.net> - 2011-06-24 01:14 +0200
      Re: offset 1 list indexing Michael Press <rubrum@pacbell.net> - 2011-06-15 15:33 -0700
    Re: offset 1 list indexing Michael Press <rubrum@pacbell.net> - 2011-06-15 15:28 -0700
      Re: offset 1 list indexing Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-15 23:34 -0400
        Re: offset 1 list indexing Michael Press <rubrum@pacbell.net> - 2011-06-15 21:42 -0700
          Re: offset 1 list indexing Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-16 08:18 -0400
            Re: offset 1 list indexing James Kuyper <jameskuyper@verizon.net> - 2011-06-16 08:32 -0400
              Re: offset 1 list indexing Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-06-16 06:29 -0700
                Re: offset 1 list indexing James Kuyper <jameskuyper@verizon.net> - 2011-06-16 09:43 -0400
              Re: offset 1 list indexing Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-16 20:50 -0400
                Re: offset 1 list indexing James Kuyper <jameskuyper@verizon.net> - 2011-06-17 08:56 -0400
                Re: offset 1 list indexing cri@tiac.net (Richard Harter) - 2011-06-17 15:11 +0000
            Re: offset 1 list indexing Michael Press <rubrum@pacbell.net> - 2011-06-16 23:54 -0700
              Re: offset 1 list indexing Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-06-23 21:45 +0300
                Re: offset 1 list indexing Tim Rentsch <txr@alumni.caltech.edu> - 2011-06-25 09:30 -0700
                Re: offset 1 list indexing pete <pfiland@mindspring.com> - 2011-06-25 13:10 -0400
                Re: offset 1 list indexing cri@tiac.net (Richard Harter) - 2011-06-25 18:18 +0000
                Re: offset 1 list indexing Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-25 15:56 -0400
                Re: offset 1 list indexing James Kuyper <jameskuyper@verizon.net> - 2011-06-25 17:42 -0400
                Re: offset 1 list indexing cri@tiac.net (Richard Harter) - 2011-06-26 04:15 +0000
                Re: offset 1 list indexing pete <pfiland@mindspring.com> - 2011-06-26 01:51 -0400
                Re: offset 1 list indexing cri@tiac.net (Richard Harter) - 2011-06-26 15:48 +0000
                Re: offset 1 list indexing pete <pfiland@mindspring.com> - 2011-06-27 00:30 -0400
                Re: offset 1 list indexing Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-06-28 21:26 +0300
                Re: offset 1 list indexing pete <pfiland@mindspring.com> - 2011-06-28 23:36 -0400
                Re: offset 1 list indexing cri@tiac.net (Richard Harter) - 2011-06-29 15:28 +0000
                Re: offset 1 list indexing pete <pfiland@mindspring.com> - 2011-06-30 15:02 -0400
                Re: offset 1 list indexing Ike Naar <ike@sverige.freeshell.org> - 2011-06-26 07:00 +0000
                Re: offset 1 list indexing cri@tiac.net (Richard Harter) - 2011-06-26 15:20 +0000
                Re: offset 1 list indexing cri@tiac.net (Richard Harter) - 2011-06-26 03:41 +0000
                Re: offset 1 list indexing Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-26 08:51 -0400
                Re: offset 1 list indexing cri@tiac.net (Richard Harter) - 2011-06-26 15:32 +0000
                Re: offset 1 list indexing Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-26 11:48 -0400
                Re: offset 1 list indexing cri@tiac.net (Richard Harter) - 2011-06-26 16:43 +0000
                Re: offset 1 list indexing Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-06-28 21:30 +0300
                Re: offset 1 list indexing Karl Malbrain <malbrain@yahoo.com> - 2011-06-28 14:13 -0700
                Re: offset 1 list indexing Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-06-28 21:14 +0300
                Re: offset 1 list indexing Tim Rentsch <txr@alumni.caltech.edu> - 2011-06-29 01:14 -0700
  Re: offset 1 list indexing Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-15 07:21 -0400
  Re: offset 1 list indexing Shao Miller <sha0.miller@gmail.com> - 2011-06-15 10:09 -0400
    Re: offset 1 list indexing Michael Press <rubrum@pacbell.net> - 2011-06-15 15:38 -0700
  Re: offset 1 list indexing China Blue Dolls <chine.bleu@yahoo.com> - 2011-06-25 21:04 -0700
    Re: offset 1 list indexing Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-26 09:01 -0400
    Re: offset 1 list indexing Michael Press <rubrum@pacbell.net> - 2011-06-26 13:15 -0700

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