std::sort_heap
Defined in header
<algorithm>
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template< class RandomIt >
void sort_heap( RandomIt first, RandomIt last ); |
(1) | |
template< class RandomIt, class Compare >
void sort_heap( RandomIt first, RandomIt last, Compare comp ); |
(2) | |
Converts the max heap [first, last)
into a sorted range in ascending order. The resulting range no longer has the heap property.
The first version of the function uses operator< to compare the elements, the second uses the given comparison function comp
.
Contents |
[edit] Parameters
first, last | - | the range of elements to sort |
comp | - | comparison function object (i.e. an object that satisfies the requirements of Compare ) which returns true if the first argument is less than the second. The signature of the comparison function should be equivalent to the following: bool cmp(const Type1 &a, const Type2 &b); The signature does not need to have const &, but the function object must not modify the objects passed to it. |
Type requirements | ||
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RandomIt must meet the requirements of ValueSwappable and RandomAccessIterator .
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-The type of dereferenced RandomIt must meet the requirements of MoveAssignable and MoveConstructible .
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[edit] Return value
(none)
[edit] Complexity
At most N×log(N) comparisons where N=std::distance(first, last).
[edit] Notes
A max heap is a range of elements [f,l)
that has the following properties:
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- *f is the largest element in the range
- a new element can be added using std::push_heap()
- the first element can be removed using std::pop_heap()
The actual arrangement of the elements is implementation defined.
[edit] Possible implementation
First version |
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template< class RandomIt > void sort_heap( RandomIt first, RandomIt last ); { while (first != last) std::pop_heap(first, last--); } |
Second version |
template< class RandomIt, class Compare > void sort_heap( RandomIt first, RandomIt last, Compare comp ); { while (first != last) std::pop_heap(first, last--, comp); } |
[edit] Example
#include <algorithm> #include <vector> #include <iostream> int main() { std::vector<int> v = {3, 1, 4, 1, 5, 9}; std::make_heap(v.begin(), v.end()); std::cout << "heap:\t"; for (const auto &i : v) { std::cout << i << ' '; } std::sort_heap(v.begin(), v.end()); std::cout << "\nsorted:\t"; for (const auto &i : v) { std::cout << i << ' '; } std::cout << '\n'; }
Output:
heap: 9 4 5 1 1 3 sorted: 1 1 3 4 5 9
[edit] See also
creates a max heap out of a range of elements (function template) |