On Friday, 26 February 2016 at 08:05:09 UTC, Joseph Rushton
Wakeling wrote:
On Thursday, 25 February 2016 at 17:27:25 UTC, Andrei
Alexandrescu wrote:
So we have
https://dlang.org/phobos/std_random.html#.randomCover which
needs to awkwardly allocate memory to keep track of the
portions of the array already covered.
Yes, this is definitely a standout in terms of being an
unpleasant solution. It means that you require o(N) memory
even when you're dealing with a lazily-evaluated range -- it
would probably be more efficient in practice to just write the
input into an array and do an in-place shuffle. :-(
Some interesting discussion/ideas here:
https://cs.stackexchange.com/questions/29822/lazily-computing-a-random-permutation-of-the-positive-integers
