| <HTML> |
| <HEAD> |
| <TITLE>stable_partition()</TITLE> |
| <LINK REL=StyleSheet HREF="../rw.css" TYPE="text/css" TITLE="Apache stdcxx Stylesheet"></HEAD> |
| <BODY BGCOLOR=#FFFFFF> |
| <A HREF="sstream-h.html"><IMG SRC="images/bprev.gif" WIDTH=20 HEIGHT=21 ALT="Previous file" BORDER=O></A><A HREF="noframes.html"><IMG SRC="images/btop.gif" WIDTH=56 HEIGHT=21 ALT="Top of Document" BORDER=O></A><A HREF="booktoc.html"><IMG SRC="images/btoc.gif" WIDTH=56 HEIGHT=21 ALT="Contents" BORDER=O></A><A HREF="tindex.html"><IMG SRC="images/bindex.gif" WIDTH=56 HEIGHT=21 ALT="Index page" BORDER=O></A><A HREF="stable-sort.html"><IMG SRC="images/bnext.gif" WIDTH=25 HEIGHT=21 ALT="Next file" BORDER=O></A><DIV CLASS="DOCUMENTNAME"><B>Apache C++ Standard Library Reference Guide</B></DIV> |
| <H2>stable_partition()</H2> |
| <P><B>Library:</B> <A HREF="2-9.html">Algorithms</A></P> |
| |
| <PRE><HR><B><I>Function</I></B><HR></PRE> |
| |
| <UL> |
| <LI><A HREF="#sec1">Local Index</A></LI> |
| <LI><A HREF="#sec2">Summary</A></LI> |
| <LI><A HREF="#sec3">Synopsis</A></LI> |
| <LI><A HREF="#sec4">Description</A></LI> |
| <LI><A HREF="#sec5">Complexity</A></LI> |
| <LI><A HREF="#sec6">Example</A></LI> |
| <LI><A HREF="#sec7">See Also</A></LI> |
| <LI><A HREF="#sec8">Standards Conformance</A></LI> |
| </UL> |
| <A NAME="sec1"><H3>Local Index</H3></A> |
| No Entries |
| <A NAME="sec2"><H3>Summary</H3></A> |
| <P>An algorithm that places all of the entities that satisfy the given predicate before all of the entities that do not, while maintaining the relative order of elements in each group</P> |
| <A NAME="sec3"><H3>Synopsis</H3></A> |
| |
| <PRE>#include <algorithm> |
| |
| namespace std { |
| template <class BidirectionalIterator, class Predicate> |
| BidirectionalIterator |
| stable_partition(BidirectionalIterator start, |
| BidirectionalIterator finish, |
| Predicate pred); |
| } |
| </PRE> |
| <A NAME="sec4"><H3>Description</H3></A> |
| <P>For the range <SAMP>[start, finish)</SAMP>, the <SAMP>stable_partition()</SAMP> algorithm places all elements that satisfy <SAMP>pred</SAMP> before all elements that do not satisfy it. It returns an iterator <SAMP>i</SAMP> that is one past the end of the group of elements that satisfies <SAMP>pred</SAMP>. The relative order of the elements in both groups is maintained. </P> |
| <P>The <SAMP><A HREF="partition.html">partition()</A></SAMP> algorithm can be used when it is not necessary to maintain the relative order of elements within the groups that do and do not match the predicate.</P> |
| <A NAME="sec5"><H3>Complexity</H3></A> |
| <P>The <SAMP>stable_partition()</SAMP> algorithm does at most <SAMP>(finish - start) * log(finish - start)</SAMP> swaps and applies the predicate exactly <SAMP>finish - start</SAMP> times. </P> |
| <A NAME="sec6"><H3>Example</H3></A> |
| |
| <UL><PRE>// |
| // prtition.cpp |
| // |
| |
| #include <algorithm> // for copy |
| #include <deque> // for deque |
| #include <functional> // for unary_function |
| #include <iostream> // for cout, endl |
| #include <iterator> // for ostream_iterator |
| |
| |
| |
| // Create a new predicate from unary_function. |
| template <class Arg> |
| struct is_even : public std::unary_function<Arg, bool> |
| { |
| bool operator()(const Arg &arg1) const { |
| return (arg1 % 2) == 0; |
| } |
| }; |
| |
| int main () |
| { |
| typedef std::deque<int, std::allocator<int> > Deque; |
| typedef std::ostream_iterator<int, char, |
| std::char_traits<char> > |
| Iter; |
| |
| // Initialize a deque with an array of integers. |
| const Deque::value_type a[] = { 1, 2, 3, 4, 5, |
| 6, 7, 8, 9, 10 }; |
| |
| Deque d1 (a + 0, a + sizeof a / sizeof *a); |
| Deque d2 (d1); |
| |
| // Print out the original values. |
| std::cout << "Unpartitioned values: \t\t"; |
| std::copy (d1.begin (), d1.end (), Iter (std::cout, " ")); |
| |
| // A partition of the deque according to even/oddness. |
| std::partition (d2.begin (), d2.end (), is_even<int>()); |
| |
| // Output result of partition. |
| std::cout << "\nPartitioned values: \t\t"; |
| std::copy (d2.begin (), d2.end (), Iter (std::cout, " ")); |
| |
| // A stable partition of the deque according to |
| // even/oddness. |
| std::stable_partition (d1.begin (), d1.end (), |
| is_even<int>()); |
| |
| // Output result of partition. |
| std::cout << "\nStable partitioned values: \t"; |
| std::copy (d1.begin (), d1.end (), Iter (std::cout, " ")); |
| std::cout << std::endl; |
| |
| return 0; |
| } |
| |
| |
| Program Files: |
| </PRE></UL> |
| <UL><PRE>Unpartitioned values: 1 2 3 4 5 6 7 8 9 10 |
| Partitioned values: 10 2 8 4 6 5 7 3 9 1 |
| Stable partitioned values: 2 4 6 8 10 1 3 5 7 9 |
| </PRE></UL> |
| <A NAME="sec7"><H3>See Also</H3></A> |
| <P><SAMP><A HREF="partition.html">partition()</A></SAMP></P> |
| <A NAME="sec8"><H3>Standards Conformance</H3></A> |
| <P><I>ISO/IEC 14882:1998 -- International Standard for Information Systems -- Programming Language C++, Section 25.2.12</I></P> |
| |
| <BR> |
| <HR> |
| <A HREF="sstream-h.html"><IMG SRC="images/bprev.gif" WIDTH=20 HEIGHT=21 ALT="Previous file" BORDER=O></A><A HREF="noframes.html"><IMG SRC="images/btop.gif" WIDTH=56 HEIGHT=21 ALT="Top of Document" BORDER=O></A><A HREF="booktoc.html"><IMG SRC="images/btoc.gif" WIDTH=56 HEIGHT=21 ALT="Contents" BORDER=O></A><A HREF="tindex.html"><IMG SRC="images/bindex.gif" WIDTH=56 HEIGHT=21 ALT="Index page" BORDER=O></A><A HREF="stable-sort.html"><IMG SRC="images/bnext.gif" WIDTH=20 HEIGHT=21 ALT="Next file" BORDER=O></A> |
| |
| <!-- Google Analytics tracking code --> |
| <script src="http://www.google-analytics.com/urchin.js" type="text/javascript"> |
| </script> |
| <script type="text/javascript"> |
| _uacct = "UA-1775151-1"; |
| urchinTracker(); |
| </script> |
| <!-- end of Google Analytics tracking code --> |
| |
| </BODY> |
| </HTML> |