On Monday, 1 May 2017 at 04:15:35 UTC, H. S. Teoh wrote:
I'm been thinking about the following problem, and thought I'd
pick the brains of the bright people around these parts...
[...]
Since most real world problems would require selecting elements
more than once it may be far more efficient to sort by
P(x)(filter) then simply select a random element.
e.g.,
a = A.filter(x->P(x)) // Creates a new set a where only the
elements of A that satisfy P(x) are added
...
e = a.random;
this is O(1) if you only have to filter once(you can create a
container that always "sorts" on P(x) so to speak.. like a sorted
dictionary).
