For the case when the search space is confined to a two-dimensional complex subspace

if the total number of an unsorted database is sufficiently large

then a unique desired state can still be found with high success probability provided any two sets of phase rotation angles

which are completely independent (unrelated to each other) but the number of elements in one of the sets is relatively small compared to the total number of an unsorted database

satisfy the multiphase matching equation.In this paper we showed that for a quantum search problem with some specific requirements

one may combine the multiphase matching equation and the classical exhaustive algorithm such that a unique desired state can be found with success probability almost close to unity.Finally

we gave a numerical example.