From: Simon Cruanes <simon.cruanes.2007@m4x.org>
To: "François Pottier" <francois.pottier@inria.fr>
Cc: jean-marc.alliot@irit.fr, caml-list@inria.fr
Subject: Re: [Caml-list] Choosing a random element in a Map or a Set
Date: Thu, 18 Mar 2021 10:20:54 -0400 [thread overview]
Message-ID: <YFNhxmn8RIuzsxsf@church> (raw)
In-Reply-To: <368aa12e-e819-4049-7ec5-4a3479f77bbb@inria.fr>
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There are some balanced trees with a weight attached to each node.
I have an implementation in containers-data
[signature](https://c-cube.github.io/ocaml-containers/3.2/containers-data/CCWBTree/module-type-S/index.html) .
There is a random_choose function that does the traversal and exploits
the weight to pick left/right for each node.
I implemented this years ago but the comments say:
Most of this comes from "implementing sets efficiently in a functional language", Stephen Adams.
The coefficients 5/2, 3/2 for balancing come from "balancing weight-balanced trees"
--
Simon Cruanes
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next prev parent reply other threads:[~2021-03-18 14:21 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-18 9:44 jean-marc.alliot
2021-03-18 10:06 ` François Pottier
2021-03-18 14:20 ` Simon Cruanes [this message]
2021-03-18 17:06 ` jean-marc.alliot
2021-03-18 11:10 ` Nicolas Barnier
2021-03-18 11:32 ` François Pottier
2021-03-19 1:32 ` Francois Berenger
2021-03-18 12:34 ` Ivan Gotovchits
2021-03-18 12:48 ` Ivan Gotovchits
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