  The present letter proposes a modification in the well known Grover's search
algorithm, which searches a database of $N$ unsorted items in $O(\sqrt{N/M})$
steps, where $M$ represents the number of solutions to the search problem.
Concurrency control techniques and extra registers for marking and storing the
solutions are used in the modified algorithm. This requires additional space
but it is shown that the use of extra register and marking techniques can
reduce the time complexity to $O(M+\log N)$.
