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 <H2>partial_sort_copy()</H2>
 <P><B>Library:</B>&nbsp;&nbsp;<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>Templatized algorithm for sorting collections of entities</P>
 <A NAME="sec3"><H3>Synopsis</H3></A>

 <PRE>#include &lt;algorithm&gt;

 namespace std {
   template &lt;class InputIterator,
             class RandomAccessIterator&gt;
   void partial_sort_copy(InputIterator start,
                          InputIterator finish,
                          RandomAccessIterator result_start,
                          RandomAccessIterator result_finish);
   template &lt;class InputIterator,
             class RandomAccessIterator,
             class Compare&gt;
   void partial_sort_copy(InputIterator start,
                          InputIterator finish,
                          RandomAccessIterator result_start,
                          RandomAccessIterator result_finish,
                          Compare comp);
 }
 </PRE>
 <A NAME="sec4"><H3>Description</H3></A>
 <P>The <SAMP>partial_sort_copy()</SAMP> algorithm places the smaller of <SAMP>finish - start</SAMP> and <SAMP>result_finish - result_start</SAMP> sorted elements from the range <SAMP>[start, finish)</SAMP> into the range beginning at <SAMP>result_start</SAMP> (in other words, the range: <SAMP>[result_start, result_start+min(finish - start, result_finish - result_start)</SAMP>). The effect is as if the range <SAMP>[start,finish)</SAMP> were placed in a temporary buffer, sorted, and then as many elements as possible copied into the range <SAMP>[result_start, result_finish)</SAMP>.</P>
 <P>The first version of the algorithm uses <SAMP>operator&lt;()</SAMP> as the comparison operator for the sort. The second version uses the function object <SAMP>comp.</SAMP></P>
 <A NAME="sec5"><H3>Complexity</H3></A>
 <P><SAMP>partial_sort_copy()</SAMP> does approximately<SAMP> (finish-start) * log(min(finish-start, result_finish-result_start))</SAMP> comparisons.</P>
 <A NAME="sec6"><H3>Example</H3></A>

 <UL><PRE>//
 //  partsort.cpp
 //

 #include &lt;algorithm&gt;   // for partial_sort
 #include &lt;iostream&gt;    // for cout, endl
 #include &lt;iterator&gt;    // for ostream_iterator
 #include &lt;vector&gt;      // for vector


 int main()
 {
     typedef std::vector&lt;int, std::allocator&lt;int&gt; &gt; Vector;

     typedef std::ostream_iterator&lt;int, char,
                                   std::char_traits&lt;char&gt; &gt;
             Iter;

     const Vector::value_type a[] = {
         17, 3,  5,  -4, 1, 12, -10, -1, 14, 7,
         -6, 8, 15, -11, 2, -2,  18,  4, -3, 0
     };

     Vector v1 (a + 0, a + sizeof a / sizeof *a);

     // Output original vector.
     std::cout &lt;&lt; "For the vector: ";
     std::copy (v1.begin (), v1.end (), Iter (std::cout, " "));

     // Partial sort the first seven elements.
     std::partial_sort (v1.begin (), v1.begin () + 7,
                        v1.end ());

     // Output result.
     std::cout &lt;&lt; "\n\nA partial_sort of seven elements "
               &lt;&lt; "gives: \n     ";
     std::copy (v1.begin (), v1.end (), Iter (std::cout, " "));
     std::cout &lt;&lt; std::endl;

     // A vector of ten elements.
     Vector v2 (Vector::size_type (10), 0);

     // Sort the last ten elements in v1 into v2.
     std::partial_sort_copy (v1.begin () + 10, v1.end (),
                             v2.begin (), v2.end ());

     // Output result.
     std::cout
         &lt;&lt; "\nA partial_sort_copy of the last ten elements "
         &lt;&lt; "gives: \n     ";
     std::copy (v2.begin (), v2.end (), Iter (std::cout, " "));

     std::cout &lt;&lt; std::endl;

     return 0;
 }


 Program Output:

 For the vector: 17 3 5 -4 1 12 -10 -1 14 7 -6 8 15 -11 2 -2
 18 4 -3 0

 A partial_sort of seven elements gives:
      -11 -10 -6 -4 -3 -2 -1 17 14 12 7 8 15 5 3 2 18 4 1 0

 A partial_sort_copy of the last ten elements gives:
      0 1 2 3 4 5 7 8 15 18
 </PRE></UL>
 <UL><PRE></PRE></UL>
 <A NAME="sec7"><H3>See Also</H3></A>
 <P><SAMP><A HREF="sort.html">sort()</A></SAMP>&#184; <SAMP><A HREF="stable-sort.html">stable_sort()</A></SAMP>, <SAMP><A HREF="partial-sort.html">partial_sort()</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 25.3.1.4</I></P>

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	<H2>partial_sort_copy()</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>Templatized algorithm for sorting collections of entities</P>
	<A NAME="sec3"><H3>Synopsis</H3></A>

	<PRE>#include <algorithm>

	namespace std {
	template <class InputIterator,
	class RandomAccessIterator>
	void partial_sort_copy(InputIterator start,
	InputIterator finish,
	RandomAccessIterator result_start,
	RandomAccessIterator result_finish);
	template <class InputIterator,
	class RandomAccessIterator,
	class Compare>
	void partial_sort_copy(InputIterator start,
	InputIterator finish,
	RandomAccessIterator result_start,
	RandomAccessIterator result_finish,
	Compare comp);
	}
	</PRE>
	<A NAME="sec4"><H3>Description</H3></A>
	<P>The <SAMP>partial_sort_copy()</SAMP> algorithm places the smaller of <SAMP>finish - start</SAMP> and <SAMP>result_finish - result_start</SAMP> sorted elements from the range <SAMP>[start, finish)</SAMP> into the range beginning at <SAMP>result_start</SAMP> (in other words, the range: <SAMP>[result_start, result_start+min(finish - start, result_finish - result_start)</SAMP>). The effect is as if the range <SAMP>[start,finish)</SAMP> were placed in a temporary buffer, sorted, and then as many elements as possible copied into the range <SAMP>[result_start, result_finish)</SAMP>.</P>
	<P>The first version of the algorithm uses <SAMP>operator<()</SAMP> as the comparison operator for the sort. The second version uses the function object <SAMP>comp.</SAMP></P>
	<A NAME="sec5"><H3>Complexity</H3></A>
	<P><SAMP>partial_sort_copy()</SAMP> does approximately<SAMP> (finish-start) * log(min(finish-start, result_finish-result_start))</SAMP> comparisons.</P>
	<A NAME="sec6"><H3>Example</H3></A>

	<UL><PRE>//
	// partsort.cpp
	//

	#include <algorithm> // for partial_sort
	#include <iostream> // for cout, endl
	#include <iterator> // for ostream_iterator
	#include <vector> // for vector



	int main()
	{
	typedef std::vector<int, std::allocator<int> > Vector;

	typedef std::ostream_iterator<int, char,
	std::char_traits<char> >
	Iter;

	const Vector::value_type a[] = {
	17, 3, 5, -4, 1, 12, -10, -1, 14, 7,
	-6, 8, 15, -11, 2, -2, 18, 4, -3, 0
	};

	Vector v1 (a + 0, a + sizeof a / sizeof *a);

	// Output original vector.
	std::cout << "For the vector: ";
	std::copy (v1.begin (), v1.end (), Iter (std::cout, " "));

	// Partial sort the first seven elements.
	std::partial_sort (v1.begin (), v1.begin () + 7,
	v1.end ());

	// Output result.
	std::cout << "\n\nA partial_sort of seven elements "
	<< "gives: \n ";
	std::copy (v1.begin (), v1.end (), Iter (std::cout, " "));
	std::cout << std::endl;

	// A vector of ten elements.
	Vector v2 (Vector::size_type (10), 0);

	// Sort the last ten elements in v1 into v2.
	std::partial_sort_copy (v1.begin () + 10, v1.end (),
	v2.begin (), v2.end ());

	// Output result.
	std::cout
	<< "\nA partial_sort_copy of the last ten elements "
	<< "gives: \n ";
	std::copy (v2.begin (), v2.end (), Iter (std::cout, " "));

	std::cout << std::endl;

	return 0;
	}


	Program Output:

	For the vector: 17 3 5 -4 1 12 -10 -1 14 7 -6 8 15 -11 2 -2
	18 4 -3 0

	A partial_sort of seven elements gives:
	-11 -10 -6 -4 -3 -2 -1 17 14 12 7 8 15 5 3 2 18 4 1 0

	A partial_sort_copy of the last ten elements gives:
	0 1 2 3 4 5 7 8 15 18
	</PRE></UL>
	<UL><PRE></PRE></UL>
	<A NAME="sec7"><H3>See Also</H3></A>
	<P><SAMP><A HREF="sort.html">sort()</A></SAMP>¸ <SAMP><A HREF="stable-sort.html">stable_sort()</A></SAMP>, <SAMP><A HREF="partial-sort.html">partial_sort()</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 25.3.1.4</I></P>

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