📄 adjacent_difference.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=NupbddFCY34AAHkj@ZY">
<img src="http://ad.doubleclick.net/ad/www.codeguru.com/cpp;ord=NupbddFCY34AAHkj@ZY"></a>
</p>
</noscript>
<BR Clear>
<H1>adjacent_difference</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>
<tt>Adjacent_difference</tt> is an overloaded name; there are actually two <tt>adjacent_difference</tt>
functions.
<pre>
template <class <A href="InputIterator.shtml">InputIterator</A>, class <A href="OutputIterator.shtml" tppabs="http://www.sgi.com/Technology/STL/OutputIterator.shtml">OutputIterator</A>>
OutputIterator adjacent_difference(InputIterator first, InputIterator last,
OutputIterator result);
template <class <A href="InputIterator.shtml">InputIterator</A>, class <A href="OutputIterator.shtml" tppabs="http://www.sgi.com/Technology/STL/OutputIterator.shtml">OutputIterator</A>, class <A href="BinaryFunction.shtml" tppabs="http://www.sgi.com/Technology/STL/BinaryFunction.shtml">BinaryFunction</A>>
OutputIterator adjacent_difference(InputIterator first, InputIterator last,
OutputIterator result,
BinaryFunction binary_op);
</pre>
<h3>Description</h3>
<tt>Adjacent_difference</tt> calculates the differences of adjacent elements
in the range <tt>[first, last)</tt>. This is, <tt>*first</tt> is assigned to
<tt>*result</tt> <A href="#1">[1]</A>, and, for each iterator <tt>i</tt> in the range <tt>[first + 1,
last)</tt>, the difference of <tt>*i</tt> and <tt>*(i - 1)</tt> is assigned to
<tt>*(result + (i - first))</tt>. <A href="#2">[2]</A>
<P>
The first version of <tt>adjacent_difference</tt> uses <tt>operator-</tt> to
calculate differences, and the second version uses a user-supplied
<A href="BinaryFunction.shtml">binary function</A>. In the first version, for each iterator
<tt>i</tt> in the range <tt>[first + 1, last)</tt>,
<tt>*i - *(i - 1)</tt> is assigned to <tt>*(result + (i - first))</tt>.
In the second version, the value that is assigned to <tt>*(result + 1)</tt>
is instead <tt>binary_op(*i, *(i - 1))</tt>.
<h3>Definition</h3>
Defined in <A href="algo.h">algo.h</A>.
<h3>Requirements on types</h3>
For the first version:
<UL>
<LI>
<tt>ForwardIterator</tt> is a model of <A href="ForwardIterator.shtml">Forward Iterator</A>.
<LI>
<tt>OutputIterator</tt> is a model of <A href="OutputIterator.shtml">Output Iterator</A>.
<LI>
If <tt>x</tt> and <tt>y</tt> are objects of <tt>ForwardIterator</tt>'s value type,
then <tt>x - y</tt> is defined.
<LI>
<tt>InputIterator</tt>s value type is convertible to a type in
<tt>OutputIterator</tt>'s set of value types.
<LI>
The return type of <tt>x - y</tt> is convertible to a type in
<tt>OutputIterator</tt>'s set of value types.
</UL>
For the second version:
<UL>
<LI>
<tt>ForwardIterator</tt> is a model of <A href="ForwardIterator.shtml">Forward Iterator</A>.
<LI>
<tt>OutputIterator</tt> is a model of <A href="OutputIterator.shtml">Output Iterator</A>.
<LI>
<tt>BinaryFunction</tt> is a model of <A href="BinaryFunction.shtml">Binary Function</A>.
<LI>
<tt>InputIterator</tt>'s value type is convertible to a
<tt>BinaryFunction</tt>'s first argument type and second argument type.
<LI>
<tt>InputIterator</tt>s value type is convertible to a type in
<tt>OutputIterator</tt>'s set of value types.
<LI>
<tt>BinaryFunction</tt>'s result type is convertible to a type in
<tt>OutputIterator</tt>'s set of value types.
</UL>
<h3>Preconditions</h3>
<UL>
<LI>
<tt>[first, last)</tt> is a valid range.
<LI>
<tt>[result, result + (last - first))</tt> is a valid range.
</UL>
<h3>Complexity</h3>
Linear. Zero applications of the binary operation if <tt>[first, last)</tt>
is an empty range, otherwise exactly <tt>(last - first) - 1</tt> applications.
<h3>Example</h3>
<pre>
int main()
{
int A[] = {1, 4, 9, 16, 25, 36, 49, 64, 81, 100};
const int N = sizeof(A) / sizeof(int);
int B[N];
cout << "A[]: ";
<A href="copy.shtml">copy</A>(A, A + N, <A href="ostream_iterator.shtml" tppabs="http://www.sgi.com/Technology/STL/ostream_iterator.shtml">ostream_iterator</A><int>(cout, " "));
cout << endl;
adjacent_difference(A, A + N, B);
cout << "Differences: ";
<A href="copy.shtml">copy</A>(B, B + N, <A href="ostream_iterator.shtml" tppabs="http://www.sgi.com/Technology/STL/ostream_iterator.shtml">ostream_iterator</A><int>(cout, " "));
cout << endl;
cout << "Reconstruct: ";
partial_sum(B, B + N, <A href="ostream_iterator.shtml">ostream_iterator</A><int>(cout, " "));
cout << endl;
}
</pre>
<h3>Notes</h3>
<P><A name="1">[1]</A>
The reason it is useful to store the value of the first element,
as well as simply storing the differences, is that this provides
enough information to reconstruct the input range. In particular,
if addition and subtraction have the usual arithmetic definitions, then
<tt>adjacent_difference</tt> and <tt><A href="partial_sum.shtml">partial_sum</A></tt> are inverses of each other.
<P><A name="2">[2]</A>
Note that <tt>result</tt> is permitted to be the same iterator as
<tt>first</tt>. This is useful for computing differences "in place".
<h3>See also</h3>
<tt><A href="partial_sum.shtml">partial_sum</A></tt>, <tt><A href="accumulate.shtml" tppabs="http://www.sgi.com/Technology/STL/accumulate.shtml">accumulate</A></tt>, <tt><A href="inner_product.shtml" tppabs="http://www.sgi.com/Technology/STL/inner_product.shtml">inner_product</A></tt>,
<tt><A href="count.shtml">count</A></tt>
<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="../www.codeguru.com/cpp/stlguide/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=NupbddFCY34AAHkj@ZY">
<img src="http://ad.doubleclick.net/ad/www.codeguru.com/cpp;ord=NupbddFCY34AAHkj@ZY"></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 + -