Win a copy of Mesos in Action this week in the Cloud/Virtualizaton forum!

# Subset of Cubes

Donald R. Cossitt
buckaroo
Ranch Hand
Posts: 401
Write an algorithm, using pseudo code, to perform one of the following tasks, and post it to the class folder by day 4. Then, choose one algorithm that was created and posted by another student to solve the same problem, and analyze the differences between the effectiveness of the two algorithms. Post the result of the analysis, and improvements to your algorithm by day 6 of the seminar. Be creative, and have fun!
Given a string of numbers, identify all of the substrings that form numbers that are divisible by 3. For example, applying the algorithm on the string 37540 should produce the following substrings (not necessarily in this order): 0; 3; 75; 54; 375; 540

I was pm'd about this this morning. While I have not been involved in the cattle drive for some time now, I have become intrigued with this assignment and have a question about what is expected in the nit picking. The expected results in any order is { 0, 3, 75, 54, 375, 540 }, but if
identify all of the substrings that form numbers that are divisible by 3
is the goal then what about 30, 45, 57, 453, etc? Or is it not 'any combonation' given the set { 3, 7, 5, 4, 0 }?

Katrina Owen
Sheriff
Posts: 1367
18
It's an interesting assignment - but I don't think it hails from the cattle drive.

Marilyn de Queiroz
Sheriff
Posts: 9063
12
Given a string of numbers, identify all of the substrings that form numbers that are divisible by 3. For example, applying the algorithm on the string 37540 should produce the following substrings (not necessarily in this order): 0; 3; 75; 54; 375; 540

... what about 30, 45, 57, 453, etc? Or is it not 'any combination' given the set { 3, 7, 5, 4, 0 }?

I would say that the numbers need to be next to each other. Since it sounds to me like you are limited to one substring, you can't leave numbers out of the middle of "37540" to get "30". The only way to do that would be to concatenate two substrings. "3" + "0".

Donald R. Cossitt
buckaroo
Ranch Hand
Posts: 401
Thanks Marilyn. And it would be an "interesting assignment" to do it both ways