Improve disjoint_set data structure

[jeremy-murphy]

Before filing

• I searched the existing issues and did not find a duplicate.
• This is a concrete proposal, not an open-ended design question.

Kind of addition

• New algorithm
• New data structure
• New property map or utility
• New I/O format reader or writer
• Extension to an existing component
• Performance improvement
• Other (specify below)

Motivation

A user requested it to be more "competitive" and "practical."

Proposed addition

Not sure yet. Need to compare with existing modern implementations first.

Relation to existing Boost.Graph components

It's hiding in the pending directory.

Prior art

https://en.wikipedia.org/wiki/Disjoint-set_data_structure?wprov=sfla1

Will add more as they become relevant.

• Reference paper or textbook (cite below)
• Implementation in another library (link below)
• None / original idea

References:

Are you willing to contribute?

• I'd like to submit the implementation as a pull request.
• I can help with review or testing, but not the implementation.
• I'm only proposing the idea.