1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___ALGORITHM_MAKE_HEAP_H 10 #define _LIBCPP___ALGORITHM_MAKE_HEAP_H 11 12 #include <__config> 13 #include <__algorithm/comp.h> 14 #include <__algorithm/comp_ref_type.h> 15 #include <__algorithm/sift_down.h> 16 #include <__iterator/iterator_traits.h> 17 18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 19 #pragma GCC system_header 20 #endif 21 22 _LIBCPP_PUSH_MACROS 23 #include <__undef_macros> 24 25 _LIBCPP_BEGIN_NAMESPACE_STD 26 27 template <class _Compare, class _RandomAccessIterator> 28 _LIBCPP_CONSTEXPR_AFTER_CXX11 void 29 __make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) 30 { 31 typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type; 32 difference_type __n = __last - __first; 33 if (__n > 1) 34 { 35 // start from the first parent, there is no need to consider children 36 for (difference_type __start = (__n - 2) / 2; __start >= 0; --__start) 37 { 38 _VSTD::__sift_down<_Compare>(__first, __last, __comp, __n, __first + __start); 39 } 40 } 41 } 42 43 template <class _RandomAccessIterator, class _Compare> 44 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 45 void 46 make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) 47 { 48 typedef typename __comp_ref_type<_Compare>::type _Comp_ref; 49 _VSTD::__make_heap<_Comp_ref>(__first, __last, __comp); 50 } 51 52 template <class _RandomAccessIterator> 53 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 54 void 55 make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) 56 { 57 _VSTD::make_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>()); 58 } 59 60 _LIBCPP_END_NAMESPACE_STD 61 62 _LIBCPP_POP_MACROS 63 64 #endif // _LIBCPP___ALGORITHM_MAKE_HEAP_H 65