Alternative to Project Euler: Open-CS- Official answers can be viewed by all | Hacker News Reader

Alternative to Project Euler: Open-CS- Official answers can be viewed by all

open-cs.net

25 pointsjimmyjim6 comments

And also, new problems can be submitted by any user as well

Maybe it's just me, but I find the problems on Open-CS poorly explained.

For example, in problem 9, it asks to find a number in a matrix 'generated by the same algorithm', but neither does it tell what that algorithm is nor is it obvious how the algorithm works, given the examples.

Similarly, in problem 20, some arbitrary tree is given with no explanation on how it is generated or what property it has, but you are asked to return the position of a given number in that tree.

In problem 22, numbers are divided into substrings, which makes no sense.

In Project Euler, the problems are carefully explained and demonstrated with a small example, so that you can concentrate on actually solving the problem instead of guessing what the author might have wanted.

Hey, lysium, It's just you :) First of all, in problem 9, 20, it's part of the problem to find the pattern :) And for the problem 22, an ARRAY of numbers is divided into substrings, which is possible ( and substring isn't necessarily a part of a char string, and the problem statement clearly defined a substring as a subset made of consecutive elements :P ) And the site is still new, so you can't judge to such a big site as Project Euler, and the existence of Open-CS doesn't eliminate that of Project Euler, no one ever said it wasn't a good site Good luck in getting problems :P

Looks interesting. I'll probably run through it, I need to brush up on Ruby... and I like the more-openness of it. The inability to converse before solving a problem has been a bit of a turn-off on Euler, IMO. I can see the reason for it, but there are times where I'd really appreciate a "cheat!" button aside from Googling - generally because I'd prefer it to not record that I solved it when I didn't.

And, just for fun, here's my answer for problem 1 there: http://www.effectedcause.com/blog/?p=228

Of course, you could recognize that it's a geometric series... and (3^15 - 1) / 2 would give you the answer, but what fun is it if you don't even get to use a simple for loop when you have a perfectly good opportunity to do so. :)

What's your simple for loop answer to problem 2? :)

Are there any good resources for improving one's approach to Project Euler (or Open CS) problems? I tend to brute force everything and would like to improve and diversify my approach. However, when I search for solutions, I tend only to find people's best-effort code, and would like to see more of a break down of multiple approaches.

This blog seems like a good start, but more diversity and comparison would be ideal: http://project-euler.blogspot.com/

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