STL Sample for the inplace_merge Function

• The Standard C++ Library included with: - Microsoft Visual C++, 32-bit Edition, version 4.2

SUMMARY

The sample code below illustrates how to use the inplace_merge and the begin and end STL functions in Visual C++.

MORE INFORMATION

Required Header

   <algorithm>

Prototype

   template<class BidirectionalIterator> inline
       void inplace_merge(BidirectionalIterator first,
                          BidirectionalIterator middle,
                          BidirectionalIterator last)

Description

The inplace_merge algorithm merges two sorted sub-sequences: [first..middle) and [middle..last) in place into a single sorted sequence [first..last). This version assumes that the ranges [first..middle) and [middle..last) are sorted using operator<. If both ranges contain equal values, the value from the first range will be stored first.

Sample Code

//////////////////////////////////////////////////////////////////////
//
// Compile options needed: /GX
//
// inplace_merge.cpp : Illustrates how to use the inplace_merge
//                     function.
//
// Functions:
//
//   inplace_merge : Merge two sorted sub-sequences in place into a
//                   single sorted list.
//
//   begin - Returns an iterator that points to the first element in a
//           sequence.
//
//   end - Returns an iterator that points one past the end of 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

#include <iostream>
#include <algorithm>
#include <functional>
#include <vector>

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] = 10 ;
    Numbers[4] = 30 ;
    Numbers[5] = 69 ;
    Numbers[6] = 96 ;
    Numbers[7] = 100;

    start = Numbers.begin() ;   // location of first
                                // element of Numbers

    end = Numbers.end() ;       // one past the location
                                // last element of Numbers

    cout << "Before calling inplace_merge\n" << endl ;

    // print content of Numbers
    cout << "Numbers { " ;
    for(it = start; it != end; it++)
        cout << *it << " " ;
    cout << " }\n" << endl ;

    //merge the elements of Numbers in place
    inplace_merge(start, start + 3, end) ;

    cout << "After calling inplace_merge\n" << endl ;

    // print content of Numbers
    cout << "Numbers { " ;
    for(it = start; it != end; it++)
        cout << *it << " " ;
    cout << " }\n" << endl ;

Program Output is:

Before calling inplace_merge

Numbers { 4 10 70 10 30 69 96 100 }

After calling inplace_merge

Numbers { 4 10 10 30 69 70 96 100 }

REFERENCES

Visual C++ Books On Line: Visual C++ Books:C/C++:Standard C++ Library Reference.