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// Copyright (C) 2005-2022 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/>.
// 25.3.9 [lib.alg.permutation.generators]
#include <algorithm>
#include <testsuite_hooks.h>
#include <testsuite_iterators.h>
using __gnu_test::test_container;
using __gnu_test::bidirectional_iterator_wrapper;
using std::next_permutation;
typedef test_container<int, bidirectional_iterator_wrapper> Container;
void
test1()
{
// Note: The standard is unclear on what should happen in this case.
// This seems the only really sensible behaviour, and what is done.
int array[] = {0};
Container con(array, array);
VERIFY(!next_permutation(con.begin(), con.end()));
}
void
test2()
{
int array[] = {0};
Container con(array, array + 1);
VERIFY(!next_permutation(con.begin(), con.end()));
}
void
test3()
{
int array[] = {0, 3};
Container con(array, array + 2);
VERIFY(next_permutation(con.begin(), con.end()));
VERIFY(array[0] == 3 && array[1] == 0);
VERIFY(!next_permutation(con.begin(), con.end()));
VERIFY(array[0] == 0 && array[1] == 3);
}
void
test4()
{
int array[6] = {0, 1, 2, 3, 4, 5};
Container con(array, array + 6);
for(int i = 0 ; i < 719; ++i)
{
int temp_array[6];
std::copy(array, array + 6, temp_array);
VERIFY(next_permutation(array, array + 6));
VERIFY(std::lexicographical_compare(temp_array, temp_array + 6,
array, array + 6));
}
VERIFY(!next_permutation(array,array + 6));
for(int i = 0; i < 6; ++i)
VERIFY(array[i] == i);
}
int main()
{
test1();
test2();
test3();
test4();
}