  Quantum Grover search algorithm can find a target item in a database faster
than any classical algorithm. One can trade accuracy for speed and find a part
of the database (a block) containing the target item even faster, this is
partial search. A partial search algorithm was recently suggested by Grover and
Radhakrishnan. Here we optimize it. Efficiency of the search algorithm is
measured by number of queries to the oracle. The author suggests new version of
Grover-Radhakrishnan algorithm which uses minimal number of queries to the
oracle. The algorithm can run on the same hardware which is used for the usual
Grover algorithm.
