Category: algorithms | Component type: function |
template <class RandomAccessIterator> bool is_heap(RandomAccessIterator first, RandomAccessIterator last); template <class RandomAccessIterator, class StrictWeakOrdering> inline bool is_heap(RandomAccessIterator first, RandomAccessIterator last, StrictWeakOrdering comp)
int A[] = {1, 2, 3, 4, 5, 6, 7}; const int N = sizeof(A) / sizeof(int); assert(!is_heap(A, A+N)); make_heap(A, A+N); assert(is_heap(A, A+N));
[1] A heap is a particular way of ordering the elements in a range of Random Access Iterators [f, l). The reason heaps are useful (especially for sorting, or as priority queues) is that they satisfy two important properties. First, *f is the largest element in the heap. Second, it is possible to add an element to a heap (using push_heap), or to remove *f, in logarithmic time. Internally, a heap is a tree represented as a sequential range. The tree is constructed so that that each node is less than or equal to its parent node.