2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/93331We investigate the power of quantum computers when they are required to return an answer that is guaranteed correct after a time that is upper-bounded by a polynomial in the worst case. In an oracle setting, it is shown that such machines can solve problems that would take exponential time on any classical bounded-error probabilistic computer.10 pages, LaTeX2e, no figuresQuantum Physicstext