That should work fine. You have an easy way to iterate over every region (just a simple for loop), and you have a way to find the neighbors of a given region. What other operations might you want to do on your regions? That might alter your choice in structures.

Looks like you've got the basics of an adjacency list there. I would personally use some form of dynamic container instead of a static array. Vector would probably be ideal since it should never change once everything is loaded. And from my perspective it provides a more intuitive/usable interface to your list of neighbors. eg. say you have 3 neighbors. How do you know you only have 3 neighbors with a static array. What data is contained in the other 3 elements of the array?

The other option would be an adjacency matrix (you're really conceptually dealing with a graph structure here). Since you've said your total map is very small, the memory overhead of a matrix should be small. On the other hand, the main advantage of a matrix over a list is faster lookups of adjacency information and you said performance is almost irrelevant.

All that being said, you're probably on the right track already for your purposes. I'd still just recommend using dynamic containers though.

Looks like you've got the basics of an adjacency list there. I would personally use some form of dynamic container instead of a static array. Vector would probably be ideal since it should never change once everything is loaded. And from my perspective it provides a more intuitive/usable interface to your list of neighbors. eg. say you have 3 neighbors. How do you know you only have 3 neighbors with a static array. What data is contained in the other 3 elements of the array?

They are storing indices, so one could just stick -1s in there for invalid entries. (and/or they could keep a count variable)

A vector list could be used (though why, unless regions actually change?), or a dynamic array, but it's probably overkill for a non-issue. I mean, worst case scenario, where all the regions are in a straight line and only have a left/right neighbor, thats wasting 256 * 4 presumably 32-bit integers, and really, they could be using bytes if they really wanted to save memory, since they have a hardcoded 256 region limit. So, basically 1MB could be lost, but only in worst case scenarios, and thats really not all that much.

Looks like you've got the basics of an adjacency list there. I would personally use some form of dynamic container instead of a static array. Vector would probably be ideal since it should never change once everything is loaded. And from my perspective it provides a more intuitive/usable interface to your list of neighbors. eg. say you have 3 neighbors. How do you know you only have 3 neighbors with a static array. What data is contained in the other 3 elements of the array?

They are storing indices, so one could just stick -1s in there for invalid entries. (and/or they could keep a count variable)

A vector list could be used (though why, unless regions actually change?), or a dynamic array, but it's probably overkill for a non-issue. I mean, worst case scenario, where all the regions are in a straight line and only have a left/right neighbor, thats wasting 256 * 4 presumably 32-bit integers, and really, they could be using bytes if they really wanted to save memory, since they have a hardcoded 256 region limit. So, basically 1MB could be lost, but only in worst case scenarios, and thats really not all that much.

I wasn't even looking at it from a memory usage perspective, but a code readability and maintainability perspective (which are really priority one in my opinion).

In the static case, you are iterating over all the elements of the container that are NOT a specific, arbitrary value.

In the dynamic case, you are iterating over all the elements of the container.

On a side note, I wouldn't even assume that a vector implementation would use less memory, as it's entirely possible that the average capacity of each vector is as large as, or even larger than, the static array.

Looks like you've got the basics of an adjacency list there. I would personally use some form of dynamic container instead of a static array. Vector would probably be ideal since it should never change once everything is loaded. And from my perspective it provides a more intuitive/usable interface to your list of neighbors. eg. say you have 3 neighbors. How do you know you only have 3 neighbors with a static array. What data is contained in the other 3 elements of the array?

They are storing indices, so one could just stick -1s in there for invalid entries. (and/or they could keep a count variable)

A vector list could be used (though why, unless regions actually change?), or a dynamic array, but it's probably overkill for a non-issue. I mean, worst case scenario, where all the regions are in a straight line and only have a left/right neighbor, thats wasting 256 * 4 presumably 32-bit integers, and really, they could be using bytes if they really wanted to save memory, since they have a hardcoded 256 region limit. So, basically 1MB could be lost, but only in worst case scenarios, and thats really not all that much.

I wasn't even looking at it from a memory usage perspective, but a code readability and maintainability perspective (which are really priority one in my opinion).

In the static case, you are iterating over all the elements of the container that are NOT a specific, arbitrary value.

In the dynamic case, you are iterating over all the elements of the container.

On a side note, I wouldn't even assume that a vector implementation would use less memory, as it's entirely possible that the average capacity of each vector is as large as, or even larger than, the static array.

Eh, it's down to personal taste, pretty much. I personally dislike Vector, only because it's so much messier than the C# equivalent. =)

That said, the vector version wouldn't waste that much memory, assuming the implementor either sets the reserve size or shrinks to fit during the construction of the regions.