Article: Q158001
Product(s): Microsoft C Compiler
Version(s): winnt:
Operating System(s):
Keyword(s): _IK
Last Modified: 05-MAY-2001
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The information in this article applies to:
- The Standard C++ Library, included with:
- *EDITOR Please do not choose this product*Microsoft Visual C++ 32-bit Edition* use 241, 265, 225, version 4.2
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SUMMARY
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The sample code below illustrates how to use the partial_sort STL function in
Visual C++.
MORE INFORMATION
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Required Header
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<algorithm>
Prototype
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template<class RandomAccessIterator> inline
void partial_sort(RandomAccessIterator first,
RandomAccessIterator middle,
RandomAccessIterator last)
NOTE: The class/parameter names in the prototype do not match the original
version in the header file. They have been modified to improve readability.
Description
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The partial_sort algorithm sorts the smallest N elements, where N = middle -
first of the sequence [first, last). The remaining elements end up in the range
[middle..last) in an undefined order.
The non-predicate version of partial_sort uses operator< for comparisons.
Sample Code
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//////////////////////////////////////////////////////////////////////
//
// Compile options needed: /GX
//
// partial_sort.cpp : Illustrates how to use the partial_sort
// function.
//
// Functions:
//
// partial_sort : Sort the smallest N elements in a sequence.
//
// Written by Kalindi Sanghrajka
// of Microsoft Product Support Services,
// Software Core Developer Support.
// Copyright (c) 1996 Microsoft Corporation. All rights reserved.
//////////////////////////////////////////////////////////////////////
// disable warning C4786: symbol greater than 255 character,
// okay to ignore
#pragma warning(disable: 4786)
#include <iostream>
#include <algorithm>
#include <functional>
#include <vector>
using namespace std;
void main()
{
const int VECTOR_SIZE = 8 ;
// Define a template class vector of int
typedef vector<int, allocator<int> > IntVector ;
//Define an iterator for template class vector of strings
typedef IntVector::iterator IntVectorIt ;
IntVector Numbers(VECTOR_SIZE) ;
IntVectorIt start, end, it ;
// Initialize vector Numbers
Numbers[0] = 4 ;
Numbers[1] = 10;
Numbers[2] = 70 ;
Numbers[3] = 30 ;
Numbers[4] = 10;
Numbers[5] = 69 ;
Numbers[6] = 96 ;
Numbers[7] = 7;
start = Numbers.begin() ; // location of first
// element of Numbers
end = Numbers.end() ; // one past the location
// last element of Numbers
cout << "Before calling partial_sort\n" << endl ;
// print content of Numbers
cout << "Numbers { " ;
for(it = start; it != end; it++)
cout << *it << " " ;
cout << " }\n" << endl ;
// sort the smallest 4 elements in the sequence
partial_sort(start, start+4, end) ;
cout << "After calling partial_sort\n" << endl ;
cout << "Numbers { " ;
for(it = start; it != end; it++)
cout << *it << " " ;
cout << " }\n" << endl ;
}
Program Output is:
Before calling partial_sort
Numbers { 4 10 70 30 10 69 96 7 }
After calling partial_sort
Numbers { 4 7 10 10 70 69 96 30 }
REFERENCES
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Visual C++ Books On Line: Visual C++ Books:C/C++:Standard C++ Library Reference.
Additional query words: STL partial_sort
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Keywords : _IK
Technology : kbVCsearch kbAudDeveloper kbVCLibrary
Version : winnt:
Issue type : kbhowto
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