It depends upon where you think calculus starts. If you take the position that calculus is the concept of limit and all its consequences, then things like exp(

It depends upon where you think calculus starts. If you take the position that calculus is the concept of limit and all its consequences, then things like exp() and log() are calculus and it's hard to get anything done in CS without those. In this view, saying that quicksort is O(n log n) is a statement of calculus. If you say that calculus is derivatives and integrals, then I'd say that calculus is not that important in a digital world, and that discrete math is much more useful. However, discrete math is harder than calculus, but you can use calculus as an approximation to the discrete answer (i.e., compute the integral if you don't know how to compute a sum, or use a derivative to approximate a difference). Ironically, this is the opposite of the old attitude that the continuous answer was the true one and the discrete answer was a poor man's approximation to the true one.