C3: Modular Arithmetic II

Problem Statement

You are given integers $n$, $a$ and $L$.

Implement an oracle $O$ satisfying the following transition on a quantum circuit $\mathrm{qc}$ with $2n$ qubits.

For any pair of integers $(x, y)$ satisfying $0 \leq x < L$ and $0 \leq y < L$, the oracle satisfies

Constraints

• $1 \leq n \leq 5$
• $0 \leq a < L \leq 2^n$
• Global phase is ignored in judge.
• Integers must be encoded by little-endian.
• The submitted code must follow the specified format:

from qiskit import QuantumCircuit, QuantumRegister
 
 
def solve(n: int, a: int, L: int) -> QuantumCircuit:
    x, y = QuantumRegister(n), QuantumRegister(n + 1)
    qc = QuantumCircuit(x, y)
    # Write your code here:
 
    return qc

Hints