📄 partition.html
字号:
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<META NAME="Author" CONTENT="Zafir Anjum">
<TITLE>MFC Programmer's SourceBook : STL Programmer's Guide</TITLE>
<META name="description"
content="A freely available implementation
of the C++ Standard Template Library, including
hypertext documentation.">
<META name="keywords"
content="generic programming, STL, standard template library">
</HEAD>
<SCRIPT LANGUAGE="JavaScript"><!--
var adcategory = "cpp";
// -->
</SCRIPT>
<body background="../../fancyhome/back.gif" bgcolor="#FFFFFF" >
<SCRIPT LANGUAGE="JavaScript"><!--
var nfrm = location.href.indexOf("_nfrm_");
var validframes = (top.frames.length > 0 && top.frames['ad'] && top.frames['logo'] );
var random = Math.random();
if( !validframes && nfrm == -1 )
{
var dclkPage = "www.codeguru.com/";
if( self.adcategory )
dclkPage += adcategory;
else
dclkPage += "mfc";
document.write('<nolayer><center>');
document.write('<iframe src="http://ad.doubleclick.net/adi/' + dclkPage + ';ord='
+ random + '" width=470 height=62 marginwidth=0 marginheight=0 hspace=0 vspace=0 '
+ 'frameborder=0 scrolling=no bordercolor="#000000">');
document.write('<a href="http://ad.doubleclick.net/jump/' + dclkPage + ';ord='
+ random + '">');
document.write('<img src="http://ad.doubleclick.net/ad/' + dclkPage + ';ord='
+ random + '" height=60 width=468>' + '</a>');
document.write('</iframe>');
document.write('</center></nolayer>');
document.write('<layer src="http://ad.doubleclick.net/adl/' + dclkPage +
';ord=' + random + '"></layer>');
document.write('<ilayer visibility=hide width=468 height=83></ilayer>');
}
// top.location = "/show.cgi?" + adcategory + "=" + location.pathname;
// -->
</SCRIPT>
<noscript>
<p align="center">
<a href="http://ad.doubleclick.net/jump/www.codeguru.com/cpp;ord=NupbFdFCY34AAHkix8Q">
<img src="http://ad.doubleclick.net/ad/www.codeguru.com/cpp;ord=NupbFdFCY34AAHkix8Q"></a>
</p>
</noscript>
<BR Clear>
<H1>partition</H1>
<Table CellPadding=0 CellSpacing=0 width=100%>
<TR>
<TD Align=left><Img src = "algorithms.gif" Alt="" WIDTH = "194" HEIGHT = "38" ></TD>
<TD Align=right><Img src = "function.gif" Alt="" WIDTH = "194" HEIGHT = "38" ></TD>
</TR>
<TR>
<TD Align=left VAlign=top><b>Category</b>: algorithms</TD>
<TD Align=right VAlign=top><b>Component type</b>: function</TD>
</TR>
</Table>
<h3>Prototype</h3>
<pre>
template <class <A href="ForwardIterator.html">ForwardIterator</A>, class <A href="Predicate.html" tppabs="http://www.sgi.com/Technology/STL/Predicate.shtml">Predicate</A>>
ForwardIterator partition(ForwardIterator first,
ForwardIterator last, Predicate pred)
</pre>
<h3>Description</h3>
<tt>Partition</tt> reorders the elements in the range <tt>[first, last)</tt> based
on the <A href="functors.html">function object</A> <tt>pred</tt>, such that
the elements that satisfy <tt>pred</tt> precede the elements
that fail to satisfy it. The postcondition is that, for some
iterator <tt>middle</tt> in the range <tt>[first, last)</tt>,
<tt>pred(*i)</tt> is <tt>true</tt> for every iterator <tt>i</tt> in the range <tt>[first, middle)</tt> and
<tt>false</tt> for every iterator <tt>i</tt> in the range <tt>[middle, last)</tt>. <A href="#1">[1]</A>
The return value of <tt>partition</tt> is <tt>middle</tt>.
<h3>Definition</h3>
Defined in <A href="algo.h">algo.h</A>.
<h3>Requirements on types</h3>
<UL>
<LI>
<tt>ForwardIterator</tt> is a model of <A href="ForwardIterator.html">Forward Iterator</A>.
<LI>
<tt>Predicate</tt> is a model of <A href="Predicate.html">Predicate</A>.
<LI>
<tt>ForwardIterator</tt>'s value type is convertible to <tt>Predicate</tt>'s
argument type.
</UL>
<h3>Preconditions</h3>
<UL>
<LI>
<tt>[first, last)</tt> is a valid range.
</UL>
<h3>Complexity</h3>
Linear. Exactly <tt>last - first</tt> applications of <tt>pred</tt>, and at most
<tt>(last - first)/2</tt> swaps.
<h3>Example</h3>
Reorder a sequence so that even numbers precede odd numbers.
<pre>
int A[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
const int N = sizeof(A)/sizeof(int);
partition(A, A + N,
<A href="unary_compose.html">compose1</A>(<A href="binder2nd.html" tppabs="http://www.sgi.com/Technology/STL/binder2nd.shtml">bind2nd</A>(<A href="equal_to.html" tppabs="http://www.sgi.com/Technology/STL/equal_to.shtml">equal_to</A><int>, 0),
<A href="binder2nd.html">bind2nd</A>(<A href="modulus.html" tppabs="http://www.sgi.com/Technology/STL/modulus.shtml">modulus</A><int>, 2)));
<A href="copy.html">copy</A>(A, A + N, <A href="ostream_iterator.html" tppabs="http://www.sgi.com/Technology/STL/ostream_iterator.shtml">ostream_iterator</A><int>(cout, " "));
// The output is "10 2 8 4 6 5 7 3 9 1". <A href="#1">[1]</A>
</pre>
<h3>Notes</h3>
<P><A name="1">[1]</A>
The relative order of elements in these two blocks is not necessarily
the same as it was in the original sequence. A different algorithm,
<tt><A href="stable_partition.html">stable_partition</A></tt>, does guarantee to preserve the relative order.
<h3>See also</h3>
<tt><A href="stable_partition.html">stable_partition</A></tt>, <A href="Predicate.html" tppabs="http://www.sgi.com/Technology/STL/Predicate.shtml">Predicate</A>, <A href="functors.html" tppabs="http://www.sgi.com/Technology/STL/functors.shtml">function object</A>
<HR SIZE="6"> <FONT SIZE="-2"> Copyright © 1996 Silicon Graphics, Inc.
<HR>
<TABLE BORDER=0 WIDTH="100%" >
<TR>
<TD WIDTH="33%"><FONT SIZE=-1><A HREF="index.html" >
STL</A></FONT></TD>
<TD WIDTH="33%">
<CENTER><FONT SIZE=-2>© Copyright 1997-1998 CodeGuru</FONT> </CENTER>
</TD>
<TD WIDTH="34%">
<DIV ALIGN=right><FONT SIZE=-1>Contact : <A HREF="mailto:webmaster@codeguru.com">webmaster@codeguru.com</A> </FONT></DIV>
</TD>
</TR>
</TABLE>
<SCRIPT LANGUAGE="JavaScript" ><!--
var adurl = "/cgi-bin/doubleclick.cgi?";
if( self.adcategory )
adurl += adcategory;
else
adurl += "mfc";
if( self.parent.norefreshad )
parent.norefreshad = false;
else if( validframes )
parent.frames['ad'].location = adurl;
if( !validframes && nfrm == -1)
{
var dclkPage = "www.codeguru.com/";
if( self.adcategory )
dclkPage += adcategory;
else
dclkPage += "mfc";
// var random = Math.random();
document.write('<nolayer><center>');
document.write('<iframe src="http://ad.doubleclick.net/adi/' + dclkPage + ';ord='
+ random + '" width=470 height=62 marginwidth=0 marginheight=0 hspace=0 vspace=0 '
+ 'frameborder=0 scrolling=no bordercolor="#000000">');
document.write('<a href="http://ad.doubleclick.net/jump/' + dclkPage + ';ord='
+ random + '">');
document.write('<img src="http://ad.doubleclick.net/ad/' + dclkPage + ';ord='
+ random + '" height=60 width=468>' + '</a>');
document.write('</iframe>');
document.write('</center></nolayer>');
document.write('<layer src="http://ad.doubleclick.net/adl/' + dclkPage +
';ord=' + random + '"></layer>');
document.write('<ilayer visibility=hide width=468 height=83></ilayer>');
}
// -->
</SCRIPT>
<!-- SCRIPT LANGUAGE="JavaScript" SRC="/global/fscript.js">
//
</SCRIPT -->
<noscript>
<p align="center">
<a href="http://ad.doubleclick.net/jump/www.codeguru.com/cpp;ord=NupbFdFCY34AAHkix8Q">
<img src="http://ad.doubleclick.net/ad/www.codeguru.com/cpp;ord=NupbFdFCY34AAHkix8Q"></a>
</p>
</noscript>
</BODY>
</HTML>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -