摘要： a·b=|a||b|cosθ=axbx+ayby a×b=|a||b|sinθ=axby-bxay=平行四边形面积 阅读全文

摘要： IntroductionMany TopCoders seem to be mortally afraid of geometry problems. I think it's safe to say that the majority of them would be in favor of a ban on TopCoder geometry problems. However, geometry is a very important part of most graphics programs, especially computer games, and geometry p 阅读全文