On Sun, Oct 9, 2011 at 10:11 PM, Lorenzo Bolla
I've implemented 3 versions of the algorithm:
a Haskell version using the standard "sort": read all the words from stdin, sort them and group them. a Haskell version using map: read all the words from stdin, stick each word in a Data.Map incrementing a counter if the word is already present in the map.
You seem to be using fromListWith which is lazy, in other words you're accumulating enormous (1 + 1 + ... + 1) thunks in your map especially with the higher word count tests. It might be that GHC is optimizing that for you but I strongly doubt it. You should probably replace it by a stricter version :
fromListWith' f xs = foldl' ins empty xs where ins m (k,x) = insertWith' f k x m
I hope that helps, otherwise it seems pretty good (but I only gave it a passing glance). -- Jedaï