2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/208144Given an item and a list of values of size $N$. It is required to decide if such item exists in the list. Classical computer can search for the item in O(N). The best known quantum algorithm can do the job in $O(\sqrt{N})$. In this paper, a quantum algorithm will be proposed that can search an unstructured list in O(1) to get the YES/NO answer with certainty.11 pagesQuantum PhysicsConstant-Time Quantum Algorithm For The Unstructured Search Problemtext