adr

Yes, sugar can be harmful, but it's hardly in the same class.

It is certainly more addictive: http://www.ncbi.nlm.nih.gov/pubmed/23719144

If you enjoyed the article you might also enjoy the follow-up by the same author, 20 years later: http://arxiv.org/pdf/hep-ph/0602037v1.pdf

It says that it would be nice for the applicant to have at least a few, not necessarily all of them.

You can also use binary search to approximate the square root of a number.

The old 17-inch Macbook Pro is still available.

Suppose x = 0 and your list is [1,2,3,2,1]. If you xor 'x' with every number in your list then x = 1^2^3^2^1, which is the same as x = (1^1)^(2^2)^3 = 0^0^3 = 3. So, x=3 is the number that wasn't repeated. This works because a^b = b^a and a^a = 0.

I have the same GPU and it works fine.

Also, living a little longer may give you a chance to enjoy what these guys are working on (a cure for aging):

http://www.mfoundation.org/

skateboarding :)