# How to find all marked items by quantum search algorithm?

We know that the Grover algorithm outputs a marked item. Now we want to know the locations of all items. I can't find any paper to solve this problem.

• Repeat will take at least $M$ more 'experiments', so the $O(\sqrt{N/M}$ becomes $O(\sqrt{NM})$, where $M$ stands for the number of right answers and $N$ stands for the total numbers of items to be searched. So unmark might be the only choice now... I think. Jun 30 at 14:21