STL Sample for the upper_bound Function (157284)

MORE INFORMATION

Required Header

   <algorithm>
				

Prototype

   template<class ForwardIterator, class T> inline
       ForwardIterator upper_bound(ForwardIterator first,
                                   ForwardIterator last,
                                   const T& value)
				

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 upper_bound algorithm returns the last location in the sequence that value can be inserted such that the order of the sequence is maintained.

upper_bound returns an iterator positioned at the location that value can be inserted in the range [first..last), or returns last if no such position exists.

upper_bound assumes the range [first ..last) is sorted using operator<.

Sample Code

////////////////////////////////////////////////////////////////////// 
// 
// Compile options needed: /GX
// 
// upper_bound.cpp : Illustrates how to use the upper_bound
//                   function.
// 
// Functions:
// 
//    upper_bound : Return the upper bound within a range.
// 
// 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, location ;

    // Initialize vector Numbers
    Numbers[0] = 4 ;
    Numbers[1] = 10;
    Numbers[2] = 10 ;
    Numbers[3] = 30 ;
    Numbers[4] = 69 ;
    Numbers[5] = 70 ;
    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

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

    //return the last location at which 10 can be inserted
    // in Numbers
    location = upper_bound(start, end, 10) ;

    cout << "Element 10 can be inserted at index "
        << location - start << endl ;
}
				

Program Output is:

Numbers { 4 10 10 30 69 70 96 100  }
				

Element 10 can be inserted at index 3