[Caml-list] Choosing a random element in a Map or a Set

[jean-marc.alliot@irit.fr]

Dear list,

I am trying to take a random element from a Map or a Set.

Currently, I generate one random int between 1 et Card(map), and I iter
until I reach this element. The solution is in O(n) which is not great...

I was about to code the following solution: take the current Map code
and add a function which follows the balanced binary tree from the root
and takes randomly a left or right turn at each node until we reach a
leaf (we only need to generate one random int and use its binary
representation to choose the left or right direction at each node). This
should be in O(log(n))

Before I start coding like an idiot:
1) Is there another, more intelligent, solution?
2) Is my solution biased? I think it is not, as long as the tree is
properly balanced but...

Thanks

Jean-Marc