Heap

Heap may refer to:

Computer science

Mathematics

Industry

Comics

Names

Place

Acronyms

See also

Heap (surname)

Heap is a surname. Notable people with the surname include

See also

Heap (comics)

The Heap is the name of several fictional comic book muck-monsters, the original of which first appeared in Hillman Periodicals' Air Fighters Comics #3 (Dec. 1942), during the period fans and historians call the Golden Age of Comic Books. The character was created by writer Harry Stein and artist Mort Leav, and revived in the 1980s by Eclipse Comics.

Similar but unrelated characters appeared in comics stories published by Skywald in the 1970s and Image Comics in the 1990s.

Publication history

Hillman

Following its debut Air Fighters Comics #3 (cover-dated Dec. 1942), the Heap reappeared as a guest character sporadically in that title. With its fourth appearance, in the by-then re-titled Airboy Comics vol. 3, #9 (Oct. 1946), it became the star of a backup feature. That feature continued until the final issue, vol. 10, #4 (May 1953). Other artists associated with Hillman's Heap include Jack Abel, Paul Reinman, and Ernie Schroeder.

In 1986, Eclipse Comics, having acquired rights to some Hillman characters, began publishing a new Airboy comic with the Heap as a supporting character. The Heap also appeared in the Eclipse title The New Wave, where the creature was considered by some members of that group to be a member. Eclipse Comics went bankrupt and ceased operations in the 1990s. Image Comics purchased the Eclipse assets, including the Heap.

Memory management

Memory management is the act of managing computer memory at the system level. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when no longer needed. This is critical to any advanced computer system where more than a single process might be underway at any time.

Several methods have been devised that increase the effectiveness of memory management. Virtual memory systems separate the memory addresses used by a process from actual physical addresses, allowing separation of processes and increasing the effectively available amount of RAM using paging or swapping to secondary storage. The quality of the virtual memory manager can have an extensive effect on overall system performance.

Dynamic memory allocation

Details

The task of fulfilling an allocation request consists of locating a block of unused memory of sufficient size. Memory requests are satisfied by allocating portions from a large pool of memory called the heap or free store. At any given time, some parts of the heap are in use, while some are "free" (unused) and thus available for future allocations.

Heap (mathematics)

In abstract algebra, a heap (sometimes also called a groud) is a mathematical generalization of a group. Informally speaking, a heap is obtained from a group by "forgetting" which element is the unit, in the same way that an affine space can be viewed as a vector space in which the 0 element has been "forgotten". A heap is essentially the same thing as a torsor, and the category of heaps is equivalent to the category of torsors, with morphisms given by transport of structure under group homomorphisms, but the theory of heaps emphasizes the intrinsic composition law, rather than global structures such as the geometry of bundles.

Formally, a heap is an algebraic structure consisting of a non-empty set H with a ternary operation denoted that satisfies

A group can be regarded as a heap under the operation . Conversely, let H be a heap, and choose an element e ∈ H. The binary operation makes H into a group with identity e and inverse . A heap can thus be regarded as a group in which the identity has yet to be decided.

Heap (data structure)

In computer science, a heap is a specialized tree-based data structure that satisfies the heap property: If A is a parent node of B then the key of node A is ordered with respect to the key of node B with the same ordering applying across the heap. A heap can be classified further as either a "max heap" or a "min heap". In a max heap, the keys of parent nodes are always greater than or equal to those of the children and the highest key is in the root node. In a min heap, the keys of parent nodes are less than or equal to those of the children and the lowest key is in the root node. Heaps are crucial in several efficient graph algorithms such as Dijkstra's algorithm, and in the sorting algorithm heapsort. A common implementation of a heap is the binary heap, in which the tree is a complete binary tree (see figure).

In a heap, the highest (or lowest) priority element is always stored at the root, hence the name heap. A heap is not a sorted structure and can be regarded as partially ordered. As visible from the heap-diagram, there is no particular relationship among nodes on any given level, even among the siblings. When a heap is a complete binary tree, it has a smallest possible height—a heap with N nodes always has log N height. A heap is a useful data structure when you need to remove the object with the highest (or lowest) priority.