Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Q&A

Welcome to Software Development on Codidact!

Will you help us build our independent community of developers helping developers? We're small and trying to grow. We welcome questions about all aspects of software development, from design to code to QA and more. Got questions? Got answers? Got code you'd like someone to review? Please join us.

Post History

60%
+1 −0
Q&A Optimized representation for sets?

I need to do a lot of calculations involving sets. There are relatively few values in the "universe" of candidates that could appear in any of the sets, but potentially very many such sets (they mi...

1 answer  ·  posted 1y ago by Karl Knechtel‭  ·  last activity 1y ago by Karl Knechtel‭

#1: Initial revision by user avatar Karl Knechtel‭ · 2023-09-14T03:46:15Z (over 1 year ago)
Optimized representation for sets?
I need to do a lot of calculations involving sets. There are relatively few values in the "universe" of candidates that could appear in any of the sets, but potentially very many such sets (they might not initially be distinct, either).

My language has a built-in (or standard library) representation for sets, but it's designed to be general-purpose - a set could contain any object (or at least any hashable object, for hash-based set representations). This makes it very inefficient: it takes a lot of space to store an internal structure (tree or hash table) along with individual objects (or at least pointers thereto), and a simple element membership test needs to either traverse a tree or check a hash table and then also compare an object for equality. To say nothing of basic union and intersection operations.

I don't need this flexibility and do need more efficiency. Is there a simple way to optimize this, taking advantage of the fact that the universe of values I need in my sets is fixed (and small)?