C++ std::make_heap with std::array
Description:
std::make_heap is defined inside the header file <algorithm> .
std::make_heap has two versions,
default (1) template <class RandomAccessIterator>
void make_heap (RandomAccessIterator first, RandomAccessIterator last);
custom (2) template <class RandomAccessIterator, class Compare>
void make_heap (RandomAccessIterator first, RandomAccessIterator last, Compare comp );
A heap is a way to organize the elements of a range that allows for fast retrieval of the element with the highest value at any moment (with pop_heap), even repeatedly, while allowing for fast insertion of new elements (with push_heap).
The element with the highest value is always pointed by first. The order of the other elements depends on the particular implementation, but it is consistent throughout all heap-related functions of this header.
The elements are compared using operator< (for the first version), or comp (for the second): The element with the highest value is an element for which this would return false when compared to every other element in the range.
Parameters:
first, last
Random-access iterators to the initial and final positions of the sequence to be transformed into a heap. The range used is [first,last), which contains all the elements between first and last, including the element pointed by first but not the element pointed by last.
comp
Binary function that accepts two elements in the range as arguments, and returns a value convertible to bool.
The value returned indicates whether the element passed as first argument is considered less than the second in the specific strict weak ordering it defines.
The function shall not modify any of its arguments.
This can either be a function pointer or a function object.
Return value:
none
Container used here: std::array, is a container that encapsulates fixed size arrays.
Example
int main () {
std::array<int, 5> v{50, 20, 30, 10, 40};
std::make_heap (v.begin(),v.end()); //heap created
std::sort_heap (v.begin(),v.end()); //sort created heap
std::cout << "sorted heap :";
for (int i=0; i<v.size(); i++)
std::cout << ' ' << v[i];
return 0;
}
/*
OUTPUT
++ -std=c++11 -o main *.cpp
sorted heap : 10 20 30 40 50
*/
OUTPUT
++ -std=c++11 -o main *.cpp
sorted heap : 10 20 30 40 50
*/
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