std::ranges::sort_heap
From cppreference.com
| Defined in header <algorithm>
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| Call signature |
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template< std::random_access_iterator I, std::sentinel_for<I> S,
class Comp = ranges::less, class Proj = std::identity >
requires std::sortable<I, Comp, Proj>
constexpr I sort_heap( I first, S last, Comp comp = {}, Proj proj = {} );
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(1) | (since C++20) |
template< ranges::random_access_range R,
class Comp = ranges::less, class Proj = std::identity >
requires std::sortable<ranges::iterator_t<R>, Comp, Proj>
constexpr ranges::borrowed_iterator_t<R>
sort_heap( R&& r, Comp comp = {}, Proj proj = {} );
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(2) | (since C++20) |
Converts the heap with respect to comp and proj that is represented by the target range [first, last) or r into a range sorted with respect to comp and proj. The heap property is no longer maintained.
If the target range does not originally represent a heap with respect to comp and proj, the behavior is undefined.
The function-like entities described on this page are algorithm function objects (informally known as niebloids), that is:
- Explicit template argument lists cannot be specified when calling any of them.
- None of them are visible to argument-dependent lookup.
- When any of them are found by normal unqualified lookup as the name to the left of the function-call operator, argument-dependent lookup is inhibited.
Parameters
| first, last | - | the iterator-sentinel pair defining the target range |
| r | - | the target range |
| comp | - | the comparator to be applied to the (projected) elements |
| proj | - | the projection to be applied to the elements |
Return value
The past-the-end iterator of the target range.
Complexity
Given N as ranges::distance(first, last) or ranges::distance(r):
1,2) At most 2N⋅log(N) applications of
comp, and twice as many applications of proj.Possible implementation
struct sort_heap_fn
{
template<std::random_access_iterator I, std::sentinel_for<I> S,
class Comp = ranges::less, class Proj = std::identity>
requires std::sortable<I, Comp, Proj>
constexpr I operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
{
auto ret{ranges::next(first, last)};
for (auto last{ret}; first != last; --last)
ranges::pop_heap(first, last, comp, proj);
return ret;
}
template<ranges::random_access_range R,
class Comp = ranges::less, class Proj = std::identity>
requires std::sortable<ranges::iterator_t<R>, Comp, Proj>
constexpr ranges::borrowed_iterator_t<R>
operator()(R&& r, Comp comp = {}, Proj proj = {}) const
{
return (*this)(ranges::begin(r),
ranges::next(ranges::begin(r), ranges::end(r)),
std::move(comp), std::move(proj));
}
};
inline constexpr sort_heap_fn sort_heap{};
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Example
Run this code
import std;
int main()
{
std::array v{3, 1, 4, 1, 5, 9};
std::print("original array: {}\n", v);
std::ranges::make_heap(v);
std::print("after make_heap: {}\n", v);
std::ranges::sort_heap(v);
std::print("after sort_heap: {}\n", v);
}
Output:
original array: [3, 1, 4, 1, 5, 9]
after make_heap: [9, 5, 4, 1, 1, 3]
after sort_heap: [1, 1, 3, 4, 5, 9]
See also
| turns a max heap into a range of elements sorted in ascending order (function template) | |
(C++20) |
checks if the given range is a max heap (algorithm function object) |
(C++20) |
finds the largest subrange that is a max heap (algorithm function object) |
(C++20) |
creates a max heap out of a range of elements (algorithm function object) |
(C++20) |
removes the largest element from a max heap (algorithm function object) |
(C++20) |
adds an element to a max heap (algorithm function object) |