Any suggestions on a book describing algorithms useful for the ITA-style problems? I looked at those problems a while back (just out of curiosity, not to get a

Any suggestions on a book describing algorithms useful for the ITA-style problems? I looked at those problems a while back (just out of curiosity, not to get a job) and realized that I didn't really know how to solve those optimization / approximate-solution-to-NP-complete problems. Is there an AI text, maybe, that would fill this gap in my knowledge?