Q157561: STL Sample for the Predicate Version of the merge Function
Article: Q157561
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
=======
The sample code below illustrates how to use the predicate version of the merge
STL function in Visual C++.
MORE INFORMATION
================
Required Header
---------------
<algorithm>
Prototype
---------
template<class InputIterator1,
class InputIterator2,
class OutputIterator
class Compare> inline
OutputIterator merge( InputIterator1 first1,
InputIterator1 last1,
InputIterator2 first2,
InputIterator2 last2
OutputIterator result,
Compare compare )
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
-----------
The merge algorithm merges two sorted sequences: [first1..last1) and
[first2..last2) into a single sorted sequence starting at result.
This version assumes that the ranges [first1..last1) and [first2..last2) are
sorted using compare function. If both ranges contain equal values, the value
from the first range will be stored first.
The result of merging overlapping ranges is undefined.
Sample Code
-----------
//////////////////////////////////////////////////////////////////////
//
// Compile options needed: /GX
//
// merge.cpp : Illustrates how to use predicate version of the merge
// function.
//
// Functions:
//
// merge : Merge two sorted sequences
// into a single sorted list.
//
// 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 <vector>
#include <list>
#include <deque>
using namespace std;
void main()
{
const int MAX_ELEMENTS = 8 ;
// Define a template class vector of int
typedef vector<int, allocator<int> > IntVector ;
//Define an iterator for template class vector of ints
typedef IntVector::iterator IntVectorIt ;
IntVector NumbersVector(MAX_ELEMENTS) ;
IntVectorIt startv, endv, itv ;
// Define a template class list of int
typedef list<int, allocator<int> > IntList ;
//Define an iterator for template class list of ints
typedef IntList::iterator IntListIt ;
IntList NumbersList ;
IntListIt first, last, itl ;
// Define a template class deque of int
typedef deque<int, allocator<int> > IntDeque ;
//Define an iterator for template class deque of ints
typedef IntDeque::iterator IntDequeIt ;
IntDeque NumbersDeque(2 * MAX_ELEMENTS) ;
IntDequeIt itd ;
// Initialize vector NumbersVector
NumbersVector[0] = 4 ;
NumbersVector[1] = 10;
NumbersVector[2] = 70 ;
NumbersVector[3] = 10 ;
NumbersVector[4] = 30 ;
NumbersVector[5] = 69 ;
NumbersVector[6] = 96 ;
NumbersVector[7] = 100;
startv = NumbersVector.begin() ; // location of first
// element of NumbersVector
endv = NumbersVector.end() ; // one past the location
// last element of NumbersVector
// sort NumbersVector, merge requires the sequences
// to be sorted
sort(startv, endv, less<int>()) ;
// print content of NumbersVector
cout << "NumbersVector { " ;
for(itv = startv; itv != endv; itv++)
cout << *itv << " " ;
cout << " }\n" << endl ;
// Initialize vector NumbersList
for(int i = 0; i < MAX_ELEMENTS; i++)
NumbersList.push_back(i) ;
first = NumbersList.begin() ; // location of first
// element of NumbersList
last = NumbersList.end() ; // one past the location
// last element of NumbersList
// print content of NumbersList
cout << "NumbersList { " ;
for(itl = first; itl != last; itl++)
cout << *itl << " " ;
cout << " }\n" << endl ;
// merge the elements of NumbersVector
// and NumbersList and place the
// results in NumbersDeque
merge(startv, endv, first, last, NumbersDeque.begin(), less<int>()) ;
cout << "After calling merge\n" << endl ;
// print content of NumbersDeque
cout << "NumbersDeque { " ;
for(itd = NumbersDeque.begin();
itd != NumbersDeque.end(); itd++)
cout << *itd << " " ;
cout << " }\n" << endl ;
}
Program Output is:
NumbersVector { 4 10 10 30 69 70 96 100 }
NumbersList { 0 1 2 3 4 5 6 7 }
After calling merge
NumbersDeque { 0 1 2 3 4 4 5 6 7 10 10 30 69 70 96 100 }
REFERENCES
==========
Visual C++ Books On Line: Visual C++ Books:C/C++:Standard C++ Library Reference.
Additional query words: STL merge
======================================================================
Keywords : _IK
Technology : kbVCsearch kbAudDeveloper kbVCLibrary
Version : winnt:
Issue type : kbhowto
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