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Grover's Search Complexity

Number of queries needed by Grover's algorithm to find an item in an unsorted database of N entries.

Formula

O(N)O(\sqrt{N})

Variables

NNumber of items in the database

Example

N = 1 000 000 → ≈ 1 000 queries instead of 500 000

Did You Know?

Grover's algorithm gives a quadratic speed-up — not exponential — but for huge databases even that is game-changing.

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