On: Algorithms, A Dropbox Challenge and Dynamic Progra...

[klochner]

You obviously missed this part:

   Just like with any dynamic programming problem, we need to produce a matrix

very nice code, I found it much clearer than the blog post

The key intuition is that by considering the items sequentially, you only care about being able to reach a given sum rather than caring about all the subsets that can reach that sum. So the performance is linear in the number of different sums rather than the number of subsets.

[btilly → klochner]

No, I didn't miss that part. I just didn't believe it.

See http://en.wikipedia.org/wiki/Dynamic_programming#Dynamic_pro.... You will find that having a table is only one of several options. The approach that I took fits the description of the second class of technique there, going bottom up.

[klochner → btilly]

I was kidding :)

seriously though, what's up with the sort() call?

[btilly → klochner]

what's up with the sort() call?

The spec for the problem he was actually trying to solve said that you needed to provide the set of activities in sorted order. The list is generated in no particular order, so I sorted them before returning them. (A Python array sort sorts the array in place.)