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// Copyright (C) 2001-2022 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/>.
// 25.3.1 algorithms, sort()
#include <algorithm>
#include <testsuite_hooks.h>
const int A[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20};
const int B[] = {10, 20, 1, 11, 2, 12, 3, 13, 4, 14, 5, 15, 6, 16, 7, 17, 8, 18, 9, 19};
const int C[] = {20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1};
const int N = sizeof(A) / sizeof(int);
const int logN = 3; // ln(N) rounded up
const int P = 7;
// comparison predicate for stable_sort: order by rightmost digit
struct CompLast
{
bool
operator()(const int x, const int y)
{ return x % 10 < y % 10; }
};
// This functor has the equivalent functionality of std::geater<>,
// but there is no dependency on <functional> and it also tracks the
// number of invocations since creation.
class Gt
{
public:
static int count() { return itsCount; }
static void reset() { itsCount = 0; }
bool
operator()(const int& x, const int& y)
{
++itsCount;
return x > y;
}
private:
static int itsCount;
};
int Gt::itsCount = 0;
// 25.3.1.2 stable_sort()
void
test02()
{
int s1[N];
std::copy(A, A + N, s1);
VERIFY(std::equal(s1, s1 + N, A));
std::stable_sort(s1, s1 + N, CompLast());
VERIFY(std::equal(s1, s1 + N, B));
std::stable_sort(s1, s1 + N);
VERIFY(std::equal(s1, s1 + N, A));
Gt gt;
gt.reset();
std::stable_sort(s1, s1 + N, gt);
VERIFY(std::equal(s1, s1 + N, C));
VERIFY(gt.count() <= N * logN * logN);
}
int
main()
{
test02();
return 0;
}