examples/manual/adj_diff.cpp

 /**************************************************************************
 *
 * adj_diff.cpp - Example program for adjacent_difference. 
 *
 * $Id: //stdlib/dev/examples/stdlib/manual/adj_diff.cpp#12 $
 *
 ***************************************************************************
 *
 * Copyright (c) 1994-2005 Quovadx,  Inc., acting through its  Rogue Wave
 * Software division. Licensed under the Apache License, Version 2.0 (the
 * "License");  you may  not use this file except  in compliance with the
 * License.    You    may   obtain   a   copy   of    the   License    at
 * http://www.apache.org/licenses/LICENSE-2.0.    Unless   required    by
 * applicable law  or agreed to  in writing,  software  distributed under
 * the License is distributed on an "AS IS" BASIS,  WITHOUT WARRANTIES OR
 * CONDITIONS OF  ANY KIND, either  express or implied.  See  the License
 * for the specific language governing permissions  and limitations under
 * the License.
 * 
 **************************************************************************/

#include <numeric>       // for adjacent_difference
#include <vector>        // for vector
#include <iostream>      // for cout
#include <iterator>      // for ostream_iterator
#include <functional>    // for multiplies

#include <examples.h>


int main ()
{
    // Typedefs for convenience.
    typedef std::vector<long, std::allocator<long> > Vector;

    typedef std::ostream_iterator <Vector::value_type,
                                   char,
                                   std::char_traits<char> > os_iter;

    // Initialize a Vector of ints from an array.
    const Vector::value_type arr [] = {
        1, 1, 2, 3, 5, 8, 13, 21, 34, 55
    };

    Vector v (arr + 0, arr + sizeof arr / sizeof *arr);

    // Two vectors initialized to all zeros for storing results.
    Vector diffs (v.size ()),
           prods (v.size ());

    // Calculate difference(s) using default operator (minus).
    std::adjacent_difference (v.begin (), v.end (), diffs.begin ());

    // Calculate difference (s) using the times operator.
    std::adjacent_difference (v.begin (), v.end (), prods.begin (),
                              std::multiplies<Vector::value_type> ());

    // Create an ostream_iterator object (for convenience).
    os_iter osit (std::cout, " ");

    // Output the results.
    std::cout << "For the vector: " << std::endl << "     ";
    std::copy (v.begin (), v.end (), osit);

    std::cout << std::endl << std::endl;

    std::cout << "The differences between adjacent elements are: "
              << std::endl << "    ";

    std::copy (diffs.begin (), diffs.end (), osit);
    std::cout << std::endl << std::endl;

    std::cout << "The products of adjacent elements are: "
              << std::endl << "     ";

    std::copy (prods.begin (), prods.end (), osit);
    std::cout << std::endl;

    return 0;
}