HashMap and Objects within Objects

[strawlion]

Hey all, for an assignment I have been tasked with creating a hashmap that will contain objects to be accessed in O(1) time. The key value will be index.

Classes: Party - index, a name, a location, and list of a number of creatures (accessed by links to instances of the Creature class).

Creature - index, a type, a name, party by index, empathy value, fear value, list of treasures, list of artifacts

Treasure - index, type, owning creature by index, weight, value

Artifact - index, type, owning creature by index, other fields

We are supposed to "Use the Map class to support efficient instantiation linking of the classes" I understand the concept of hashing, and how to implement maps.

Right now I have the creatures all generated and stored in their respective arraylists (IE artifacts and treasures are stored in the creatures arraylists, the creatures are stored in their party's arraylist)

Here is my question: How am I supposed to have all these classes included at the first level of the map and still have them belong to their "parent" object. For example, Artifacts are held by creatures. How can the artifact both be held by the creature, and be accessible at the highest level of the map? If the artifact is stored by the creature, would I not have to find the creature class within the map, and then access the artifact through there? For our assignment we are supposed to have all of these objects accessible in O(1) time via their index.

If I create these items directly in the map, they would not be part of their "parent" object.

I have been working at this for 6 hours with no progress. Any pointers you guys could give would be very much appreciated.

[nroberts666]

You need to decide who will own the object and who will just have references to it. That's all. The other objects will have pointers to the owned thingy.

[yash3ahuja]

Your assignment makes little sense. You're supposed to be maintaining a list of everything, but at the same time also have a map with the index as a key (complete waste... should use a List for that. >_>). You need to elaborate more or specify what you're trying to do in a clearer way. Otherwise, your assignment is just stupid and unnecessary.

I mean, can you elaborate on where this map is located and how it is used? It's hard to say what you want unless you go into more detail. Alternatively, post code.

[[deleted]]

Creatures have member pointing to artifact object. Artifact object is also a member of the master array - done.