std::ranges::sort_heap
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 > |
(1) | (since C++20) |
template< ranges::random_access_range R, class Comp = ranges::less, class Proj = std::identity > |
(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.
[
first,
last)
.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 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.
In practice, they may be implemented as function objects, or with special compiler extensions.
Parameters
first, last | - | the iterator and sentinel designating 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
Complexity
At most 2N⋅log(N) applications of comp and 4N⋅log(N) applications of proj, where N is:
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 (; 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
#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 (niebloid) |
(C++20) |
finds the largest subrange that is a max heap (niebloid) |
(C++20) |
creates a max heap out of a range of elements (niebloid) |
(C++20) |
removes the largest element from a max heap (niebloid) |
(C++20) |
adds an element to a max heap (niebloid) |
turns a max heap into a range of elements sorted in ascending order (function template) |