Syntax:

    #include <algorithm>
    bool is_heap(iterator start, iterator end);
    bool is_heap(iterator start, iterator end, StrictWeakOrdering cmp);

The is_heap() function returns true if the given range [start,end) is a heap.

If the strict weak ordering comparison function object cmp is given, then it is used instead of the < operator to compare elements.

todo

todo

linear time

make_heap, pop_heap, push_heap, sort_heap