Add 'subsequences' and 'permutations' to Data.List (ticket
gale at sefer.org
Sat Dec 22 13:28:17 EST 2007
Twan van Laarhoven wrote:
> permutations7': 4.750 sec
> permutations7', using 3 for recursion: 4.250 sec
> permutations8: 3.984 sec
> permutations8b: 2.250 sec
> permutations8b, using 3 for recursion: 1.984 sec
> My current preference is 8 or 8b, using a different function in the
> recursion is going to far for my taste.
Perhaps they could be combined somehow, e.g., re-use
You should run your times with a control that just adds
up 10! copies of [1..10]. On my machine, that takes about
So when we subtract out the control, satisfying the consistency
property increases run time by at least a factor of 4.
The property is nice, but is it worth that penalty?
I'm not sure, I'd be interested in hearing other people's
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