Manlio Perillo ha scritto:
minh thu ha scritto:
[...]
The approach I suggested is a bit overkill. You can indeed use L.lines
to split the input into lines then work on that.
But still, avoid the pair (Int, Bytestring). Instead, you can
basically map
on each line the unsafeReadInt modified to :
- return the id
- return if it is one kind of id or the other kind.
so :
type UserId = Int
type MovieId = Int
unsafeReadInt :: Line -> Either MovieId UserId
Now you have a nice list [Either MovieId UserId] that
you need to transform into (MovieId, [UserId]).
Thanks, this seems a much better solution.
Done:
http://hpaste.org/fastcgi/hpaste.fcgi/view?id=2309
real 1m15.220s
user 0m4.816s
sys 0m0.308s
3084 KB memory usage
Previous version required 4956 KB of memory.
Thanks again for the suggestion, Minh.
Manlio
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