In this problem, the value of the function we're evaluating does not depend on the state of the qubits before qubit $P$ or after qubit $P + K - 1$. This means that we can just ignore them and consider only the qubits that matter - `x[p .. p + Length(r) - 1]`.
Once we do that, the problem becomes much simpler: flip the state of the target qubit if the input qubits are in the given state. That's the definition of a controlled gate with arbitrary controls, and we can apply that easily using the library operation `ApplyControlledOnBitString`.
@[solution]({
"id": "marking_oracles__contains_substring_p_solution",
"codePath": "./Solution.qs"
})microsoft/qdk
Publicmirrored fromhttps://github.com/microsoft/qdkAvailable
katas/content/marking_oracles/contains_substring_p/solution.md
8lines · modepreview