examples/manual/sort.cpp

/**************************************************************************
 *
 * sort.cpp - Example program of sort algorithm. See Class Reference Section
 *
 * $Id: //stdlib/dev/examples/stdlib/manual/sort.cpp#15 $
 *
 ***************************************************************************
 *
 * 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 <algorithm>    // for sort
#include <iostream>     // for cout
#include <utility>      // for pair
#include <vector>       // for vector

#include <examples.h>


typedef std::pair<int, char> Pair;

struct PairCompare
{
    bool operator() (const Pair &x, const Pair &y) const {
        return x.first < y.first;
    }
};

inline std::ostream& operator<< (std::ostream &s, const Pair &x)
{
    return s << '<' << x.first << ';' << x.second << '>';
}

int main ()
{
    const Pair array[] = {
        Pair (-4, ' '), Pair (16, ' '), Pair (17, ' '), Pair (-3, 's'),
        Pair (14, ' '), Pair (-6, ' '), Pair (-1, ' '), Pair (-3, 't'),
        Pair (23, ' '), Pair (-3, 'a'), Pair (-2, ' '), Pair (-7, ' '),
        Pair (-3, 'b'), Pair (-8, ' '), Pair (11, ' '), Pair (-3, 'l'),
        Pair (15, ' '), Pair (-5, ' '), Pair (-3, 'e'), Pair (15, ' ')
    };

    typedef std::vector<Pair, std::allocator<Pair> > Vector;

    const Vector::size_type array_size = sizeof array / sizeof *array;

    // Create two modifiable sequences.
    Vector v1 (array, array + array_size);
    Vector v2 (v1);

    // Sort vector #1.
    std::sort (v1.begin (), v1.end (), PairCompare ());

    // Stable sort vector #2.
    std::stable_sort (v2.begin (), v2.end (), PairCompare ());

    // Display the original and the sorted sequences.
    std::cout << "original   std::sort  std::stable_sort\n";

    for (Vector::size_type i = 0; i != array_size; ++i)
        std::cout << array [i] << "     "
                  << v1 [i] << "     "
                  << v2 [i] << '\n';

    return 0;
}