Hmm... I'm trying to balance "...a non-technical friend..." against "...P, the class of problems with polynomial-time algorithms, and NP, a class of problems fo

Hmm... I'm trying to balance "...a non-technical friend..." against "...P, the class of problems with polynomial-time algorithms, and NP, a class of problems for which polynomial-time algorithms are not known...". I think this post says as much about computer scientists as it does about computer science.