Difference between priority queue and a heap

Solution 1:

A priority queue is an abstract datatype. It is a shorthand way of describing a particular interface and behavior, and says nothing about the underlying implementation.

A heap is a data structure. It is a name for a particular way of storing data that makes certain operations very efficient.

It just so happens that a heap is a very good data structure to implement a priority queue, because the operations which are made efficient by the heap data strucure are the operations that the priority queue interface needs.

Solution 2:

Having a class with exactly the interface you need (just insert and pop-max?) has its advantages.

• You can exchange the implementation (list instead of heap, for example) later.
• Someone reading the code that uses the queue doesn't need to understand the more difficult interface of the heap data structure.

I guess my question is whether having a collection of functions is equivalent to storing them in some class and using them through a class or just using the functions themselves.

It's mostly equivalent if you just think in terms of "how does my program behave". But it's not equivalent in terms of "how easy is my program to understand by a human reader"

Solution 3:

The term priority queue refers to the general data structure useful to order priorities of its element. There are multiple ways to achieve that, e.g., various ordered tree structures (e.g., a splay tree works reasonably well) as well as various heaps, e.g., d-heaps or Fibonacci heaps. Conceptually, a heap is a tree structure where the weight of every node is not less than the weight of any node in the subtree routed at that node.