std::ranges::sort_heap
From cppreference.com
| Defined in header <algorithm>
|
||
| Call signature |
||
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 = {} ); |
(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 = {} ); |
(2) | (since C++20) |
Sorts the elements in the specified range with respect to comp and proj, where the range originally represents a heap with respect to comp and proj. The sorted range no longer maintains the heap property.
1) The specified range is
[first, last).2) The specified range is
r.If the specified range is not 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 range of elements to modify |
| r | - | the range of elements to modify
|
| comp | - | comparator to apply to the projected elements |
| proj | - | projection to apply to the elements |
Return value
1)
last2)
ranges::end(r)Complexity
At most 2N⋅log(N) applications of comp and 4N⋅log(N) applications of proj, where N is:
1)
ranges::distance(first, last)2)
ranges::distance(r)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::end(r), std::move(comp), std::move(proj));
}
};
inline constexpr sort_heap_fn sort_heap{};
|
Example
Run this code
#include <algorithm>
#include <array>
#include <iostream>
void print(auto const& rem, const auto& v)
{
std::cout << rem;
for (const auto i : v)
std::cout << i << ' ';
std::cout << '\n';
}
int main()
{
std::array v{3, 1, 4, 1, 5, 9};
print("original array: ", v);
std::ranges::make_heap(v);
print("after make_heap: ", v);
std::ranges::sort_heap(v);
print("after sort_heap: ", 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
(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) |
| turns a max heap into a range of elements sorted in ascending order (function template) |