| // Copyright (C) 2006-2023 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/>. |
| |
| // 25.3.2 [lib.alg.nth.element] |
| |
| // { dg-options "-DMAX_SIZE=256" { target simulator } } |
| |
| #ifndef MAX_SIZE |
| #define MAX_SIZE (1 << 10) |
| #endif |
| |
| #include <vector> |
| #include <algorithm> |
| #include <testsuite_hooks.h> |
| |
| void |
| test_set(std::vector<unsigned>& v, unsigned size) |
| { |
| v.clear(); |
| |
| for (unsigned i = 0; i < size; i += 4) |
| { |
| v.push_back(i / 2); |
| v.push_back((size - 2) - (i / 2)); |
| } |
| for (unsigned i = 1; i < size; i += 2) |
| v.push_back(i); |
| } |
| |
| void |
| do_test01(unsigned size) |
| { |
| std::vector<unsigned> v, s; |
| |
| for (unsigned j = 0; j < size; ++j) |
| { |
| test_set(v, size); |
| s = v; |
| std::sort(s.begin(), s.end()); |
| |
| std::nth_element(v.begin(), v.begin() + j, v.end()); |
| |
| VERIFY( v[j] == s[j] ); |
| |
| for (unsigned i = 0; i < j; ++i) |
| VERIFY( !(v[j] < v[i]) ); |
| |
| for (unsigned i = j; i < v.size(); ++i) |
| VERIFY( !(v[i] < v[j]) ); |
| } |
| } |
| |
| void |
| test01() |
| { |
| for (unsigned size = 4; size <= MAX_SIZE; size <<= 1) |
| do_test01(size); |
| } |
| |
| int main() |
| { |
| test01(); |
| return 0; |
| } |