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// -*- C++ -*-

// Copyright (C) 2005, 2006, 2009 Free Software Foundation, Inc.

//

// This file is part of the GNU ISO C++ Library.  This library is free

// software; you can redistribute it and/or modify it under the terms

// of the GNU General Public License as published by the Free Software

// Foundation; either version 3, or (at your option) any later

// version.

// This library is distributed in the hope that it will be useful, but

// WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

// General Public License for more details.

// You should have received a copy of the GNU General Public License

// along with this library; see the file COPYING3.  If not see

// <http://www.gnu.org/licenses/>.

// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.

// Permission to use, copy, modify, sell, and distribute this software

// is hereby granted without fee, provided that the above copyright

// notice appears in all copies, and that both that copyright notice

// and this permission notice appear in supporting documentation. None

// of the above authors, nor IBM Haifa Research Laboratories, make any

// representation about the suitability of this software for any

// purpose. It is provided "as is" without express or implied

// warranty.

/**

 * @file tree_join_example.cpp

 * An example showing how to join splay_tree_map objects.

 *    The code in the example is relevant to red-black trees as well.

 */

/**

 * This example shows how to join tree based containers, i.e., taking two

 *     objects with non-overlapping sets of keys and combining them into

 *    a single object.

 */

// For tree

#include <ext/pb_ds/assoc_container.hpp>

// For join_error exception.

#include <ext/pb_ds/exception.hpp>

// For assert

#include <cassert>

using namespace std;

using namespace __gnu_pbds;

using namespace __gnu_pbds;

int main()

{

  /*

   *

   */

  // A splay tree table mapping ints to chars.

  typedef tree<int, char, less<int>, splay_tree_tag> map_t;

  // Two map_t object.

  map_t h0, h1;

  // Insert some values into the first table.

  for (int i0 = 0; i0 < 100; ++i0)

    h0.insert(make_pair(i0, 'a'));

  // Insert some values into the second table.

  for (int i1 = 0; i1 < 100; ++i1)

    h1.insert(make_pair(1000 + i1, 'b'));

  // Since all the elements in h0 are smaller than those in h1, it is

  // possible to join the two tables. This is exception free.

  h0.join(h1);

  // Check that h0 should now contain all entries, and h1 should be empty.

  assert(h0.size() == 200);

  assert(h1.empty());

  // Two other map_t objects.

  map_t h2, h3;

  h2[1] = 'a';

  h2[3] = 'c';

  h3[2] = 'b';

  // Now perform an illegal join.

  // It is not true that all elements in h2 are smaller than those in

  // h3, nor is it true that they are all larger. Hence, attempting to

  // join h2, and h3 should result in an exception.

  bool exception_thrown = false;

  try

    {

      h2.join(h3);

    }

  catch (__gnu_pbds::join_error& )

    {

      exception_thrown = true;

    }

  assert(exception_thrown);

  // Since the operation was not performed, the tables should be unaltered.

  assert(h2.size() == 2);

  assert(h3[2] == 'b');

  return 0;

}