98 lines
3.5 KiB
HTML
98 lines
3.5 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN">
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<HTML>
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<HEAD>
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<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
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<META NAME="AUTHOR" CONTENT="pme@sources.redhat.com (Phil Edwards)">
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<META NAME="KEYWORDS" CONTENT="HOWTO, libstdc++, GCC, g++, libg++, STL">
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<META NAME="DESCRIPTION" CONTENT="HOWTO for the libstdc++ chapter 25.">
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<META NAME="GENERATOR" CONTENT="vi and eight fingers">
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<TITLE>libstdc++-v3 HOWTO: Chapter 25</TITLE>
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<LINK REL="home" HREF="http://sources.redhat.com/libstdc++/docs/25_algorithms/">
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<LINK REL=StyleSheet HREF="../lib3styles.css">
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<!-- $Id: howto.html,v 1.3 2000/07/11 21:45:08 pme Exp $ -->
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</HEAD>
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<BODY>
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<H1 CLASS="centered"><A NAME="top">Chapter 25: Algorithms</A></H1>
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<P>Chapter 25 deals with the generalized subroutines for automatically
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transforming lemmings into gold.
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</P>
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<!-- ####################################################### -->
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<HR>
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<H1>Contents</H1>
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<UL>
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<LI><A HREF="#1">Prerequisites</A>
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<LI><A HREF="#2">Topic</A>
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</UL>
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<HR>
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<!-- ####################################################### -->
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<H2><A NAME="1">Prerequisites</A></H2>
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<P>The neatest accomplishment of the algorithms chapter is that all the
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work is done via iterators, not containers directly. This means two
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important things:
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<OL>
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<LI>Anything that behaves like an iterator can be used in one of
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these algorithms. Raw pointers make great candidates, thus
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built-in arrays are fine containers. So do your own iterators.
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<LI>The algorithms do not (and cannot) affect the container as a
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whole; only the things between the two iterator endpoints. If
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you pass a range of iterators only enclosing the middle third of
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a container, then anything outside that range is inviolate.
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</OL>
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</P>
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<P>Even strings can be fed through the algorithms here, although the
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string class has specialized versions of many of these functions (for
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example, <TT>string::find()</TT>). Most of the examples on this
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page will use simple arrays of integers as a playground for
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algorithms, just to keep things simple.
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<A NAME="Nsize">The use of <B>N</B></A> as a size in the examples is
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to keep things easy to read but probably won't be legal code. You can
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use wrappers such as those described in the
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<A HREF="../23_containers/howto.html">containers chapter</A> to keep
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real code readable.
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</P>
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<P>The single thing that trips people up the most is the definition of
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<EM>range</EM> used with iterators; the famous
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"past-the-end" rule that everybody loves to hate. The
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<A HREF="../24_iterators/howto.html">iterators chapter</A> of this
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document has a complete explanation of this simple rule that seems to
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cause so much confusion. Once you get <EM>range</EM> into your head
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(it's not that hard, honest!), then the algorithms are a cakewalk.
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</P>
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<P>
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</P>
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<P>Return <A HREF="#top">to top of page</A> or
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<A HREF="../faq/index.html">to the FAQ</A>.
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</P>
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<HR>
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<H2><A NAME="2">Topic</A></H2>
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<P>Blah.
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</P>
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<P>Return <A HREF="#top">to top of page</A> or
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<A HREF="../faq/index.html">to the FAQ</A>.
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</P>
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<!-- ####################################################### -->
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<HR>
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<P CLASS="fineprint"><EM>
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Comments and suggestions are welcome, and may be sent to
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<A HREF="mailto:pme@sources.redhat.com">Phil Edwards</A> or
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<A HREF="mailto:gdr@gcc.gnu.org">Gabriel Dos Reis</A>.
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<BR> $Id: howto.html,v 1.3 2000/07/11 21:45:08 pme Exp $
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</EM></P>
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</BODY>
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</HTML>
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