Standard C++	Library
 		 Copyright 1996, Rogue Wave Software, Inc.

 NAME

   partial_sort_copy  - Templated algorithm for sorting collections of
   entities.

 SYNOPSIS

   #include <algorithm>

   template <class InputIterator,
 	   class RandomAccessIterator>
   void partial_sort_copy (InputIterator	first,
 			  InputIterator	last,
 			  RandomAccessIterator result_first,
 			  RandomAccessIterator result_last);
   template <class InputIterator,
 	   class RandomAccessIterator,
 	   class Compare>
   void partial_sort_copy (InputIterator	first,
 			  InputIterator	last,
 			  RandomAccessIterator result_first,
 			  RandomAccessIterator result_last,
 			  Compare comp);

 DESCRIPTION

   The partial_sort_copy	algorithm places the smaller of	last - first
   and result_last -	result_first  sorted elements from the range
   [first, last) into the range beginning at result_first. (i.e., the
   range: [result_first, result_first+min(last	- first, result_last -
   result_first)).	Basically, the effect is	as if the
   range	[first,last) were placed in a temporary buffer, sorted and
   then as many elements as possible were copied into	the range
   [result_first, result_last).

   The first version of the algorithm uses less than (operator<)	as the
   comparison operator  for	the sort.  The second version uses the
   comparison function comp.

 COMPLEXITY

   partial_sort_copy does approximately (last-first) * log(min(last-first,
   result_last-result_first)) comparisons.

 EXAMPLE

   //
   // partsort.cpp
   // #include <vector>
    #include <algorithm>
    #include <iostream.h>
   int main()
    {
     int	d1[20] = {17, 3,  5,  -4, 1, 12, -10, -1, 14, 7,
 		   -6, 8, 15, -11, 2, -2,  18,	4, -3, 0};
      //
      //	Set up a vector.
      //
     vector<int>	v1(d1+0, d1+20);
      //
      //	Output original	vector.
      //
     cout << "For the vector: ";
     copy(v1.begin(), v1.end(), ostream_iterator<int>(cout," "));
      //
      //	Partial	sort the first seven elements.
      //
     partial_sort(v1.begin(), v1.begin()+7, v1.end());
      //
      //	Output result.
      //
     cout << endl << endl << "A partial_sort of 7 elements gives: "
 	  << endl << "	   ";
     copy(v1.begin(), v1.end(),
 	 ostream_iterator<int,char>(cout," "));
     cout << endl;
      //
      //	A vector of ten	elements.
      //
     vector<int>	v2(10, 0);
      //
      //	Sort the last ten elements in v1 into v2.
      //
      partial_sort_copy(v1.begin()+10, v1.end(),	v2.begin(),
 			  v2.end());
      //
      //	Output result.
      //
     cout << endl << "A partial_sort_copy of the	last ten elements
 			gives: " << endl << "	  ";
     copy(v2.begin(), v2.end(),
 	 ostream_iterator<int,char>(cout," "));
     cout << endl;
     return 0;
    }
   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

 WARNING

   If your compiler does	not support default template parameters, then
   you need to always provide the Allocator template	argument.  For
   instance, you will need to write :

   vector<int, allocator<int> >

   instead of :

   vector<int>

 SEE ALSO

   sort_	stable_sort, partial_sort

 STANDARDS CONFORMANCE
   ANSI X3J16/ISO WG21 Joint C++	Committee