> So a quantum calculation is more a probabilistic restriction on which state you want, rather than a direct calculation. Not necessarily, some quantum algorit

> So a quantum calculation is more a probabilistic restriction on which state you want, rather than a direct calculation. Not necessarily, some quantum algorithms give an answer with 100% probability (like the Deutch-Josza algorithm). You're right in that the two most interesting ones (Grover's and Shor's algorithms) are probabilistic, though.