Comments on: Justin Etheredge’s LINQ Challenge

By: The TekPub LINQ Challenge Part 2 – Faster Algorithms | CodeThinked

The TekPub LINQ Challenge Part 2 – Faster Algorithms | CodeThinked — Fri, 18 Feb 2011 22:21:49 +0000

[...] my friend Nate over at Kohari.org created an implementation very similar to mine, but had one major difference, and that was leveraging the fact that for any number, in order to [...]

By: Nate

Nate — Mon, 18 Jan 2010 13:43:27 +0000

M@: LINQ (at least LINQ to Objects, which is what we’re talking about here) doesn’t really have anything to do with databases. The syntax is reminiscent of SQL, but it’s just intended to operate on collections of objects in memory.

By: M@

M@ — Wed, 13 Jan 2010 20:30:30 +0000

this is going to seem like a moronic question, but why create a programming language around sql? I know NOTHING about LINQ so you can feel free to tell me to RTFM

I’m working in a company that is about to start in on a lot of BI stuff, so I’m curious to learn more about LINQ.

By: Conker

Conker — Tue, 12 Jan 2010 15:37:18 +0000

Hello Nate, not trying to take a credit, its a cleaned up version of your query
To be compatible with chanllenge, the first check x != 1 can be left as it is, it doesnt affect speed as much as second check x!=y, which is completely unnecessary.
Challenge aside, i think this cleaned version is as very elegant , simple and truly shows the power of LINQ.

By: Nate

Nate — Tue, 12 Jan 2010 13:47:02 +0000

@Conker:

The challenge said the beginning of the statement had to start with Enumerable.Range(1, max) … otherwise I’d agree.

By: Conker

Conker — Tue, 12 Jan 2010 11:48:35 +0000

More compact and faster variant :

int max = …
var primes = Enumerable.Range(2, max-1).Where(x => !Enumerable.Range(2, (int)Math.Sqrt(x)-1).Any(y =>x % y == 0));

By: Yex

Yex — Sat, 09 Jan 2010 01:41:07 +0000

Thanks for the post. I’d love a subscription to TekPub. I figured the other guy didn’t leave an email address, so maybe I still had a shot, eh? ; )

By: Nate

Nate — Sat, 09 Jan 2010 01:40:23 +0000

@Rene: It’s yours. Send me an email (nate@enkari.com) with your info and I’ll pass it along to Justin.

By: Rene

Rene — Sat, 09 Jan 2010 01:38:49 +0000

i want the suscription =D