finding most common elements between thousands of multiple arrays.

Emile van Sebille emile at
Sun Jul 5 03:00:29 CEST 2009

On 7/4/2009 12:33 AM mclovin said...
> Currently I need to find the most common elements in thousands of
> arrays within one large array (arround 2 million instances with ~70k
> unique elements)
> so I set up a dictionary to handle the counting so when I am
> iterating  I 

   ** up the count on the corrosponding dictionary element **

Right at this point, instead of or in addition to counting, why not save 
the large array index in a list?  Then when you've identified the 25 
most common elements you'll already have a list of pointer to the 
instances to work from.


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