Exact Grover search on four entries
= Exact Grover search on four entries
For $N=4$ and one marked item, $\theta=\pi/6$. One Grover iteration gives marked amplitude $\sin(3\theta)=1$, so measurement returns the target with certainty.
= Exact Grover search on four entries
For $N=4$ and one marked item, $\theta=\pi/6$. One Grover iteration gives marked amplitude $\sin(3\theta)=1$, so measurement returns the target with certainty.