Editing Quantum algorithm (section)

===Deutsch–Jozsa algorithm===
{{main|Deutsch–Jozsa algorithm}}

[[File:Deutsch-Jozsa-algorithm-quantum-circuit.png|thumb|Deutsch-Jozsa algorithm]]
The Deutsch–Jozsa algorithm solves a [[black-box]] problem that requires exponentially many queries to the black box for any deterministic classical computer, but can be done with a single query by a quantum computer. However, when comparing bounded-error classical and quantum algorithms, there is no speedup, since a classical probabilistic algorithm can solve the problem with a constant number of queries with small probability of error. The algorithm determines whether a function ''f'' is either constant (0 on all inputs or 1 on all inputs) or balanced (returns 1 for half of the input domain and 0 for the other half).