Heap: Memory Allocation or Data Structure? A Tale of Two Terms.

Heap: A Double-Edged Term in Computer Science

The term "heap" appears twice in computer science, representing distinct concepts that may leave some puzzled. One concept refers to the runtime heap used for dynamic memory allocation in C-style languages, while the other denotes a specific data structure used for priority queues. So, why this overlap in terminology?

The Runtime Heap

According to Donald Knuth in "The Art of Computer Programming," the term "heap" was first applied to the runtime heap by various authors around 1975. This usage originated from the analogy to a physical heap, a pile of items that can be added or removed at any point. In the context of memory management, the runtime heap acts as a pool of available memory where dynamic memory allocation occurs.

Priority Queue Heaps

Separately, the term "heap" has been used to describe a data structure that organizes elements based on a key into a partially ordered binary tree. This data structure is particularly useful for implementing priority queues, where the highest (or lowest) priority element can be retrieved in constant time.

Is There a Connection?

Despite the shared nomenclature, there is no direct relation between the runtime heap and priority queue heaps. The former is a concept related to memory allocation and management, while the latter is a data structure with a specific structure and properties.

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