[Haskell-cafe] looking for a good algorithm

Hong Yang hyangfji at gmail.com
Fri Nov 13 23:13:50 EST 2009

Hi Casey,

Thanks very much for your zeal.

The table is a csv file. Actually the number of rows can be sixty thousand.


On Fri, Nov 13, 2009 at 5:08 PM, Casey Hawthorne <caseyh at istar.ca> wrote:

> Sorry, I forgot to ask an important question.
> Is the table stored
> in a dense format as in complete rows and complete columns
> or
> in a sparse table format?
> >The question is more about algorithm than Haskell. But I am going to code
> in Haskell which I am still learning.
> >Suppose I have a large table, with hundreds of columns and thousands of
> rows. But not every cell has a value (of String, or Int, or Double type).
> >I want to shuffle the rows to maximize the number of columns whose first
> 100 rows have at least one number, given a list of preferred column names
> since there is no guarantee that every number column will have at least one
> number in its first 100 rows after shuffling.
> >Can someone provide a good algorithm for this problem? (I do not have any
> background in algorithms.) You can assume I already know which columns are
> of Int or Double type.
> --
> Regards,
> Casey
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