Implementing Grover's algorithm on 4 qubits

Question

I have the below Oracle function.

Below are the marked states for this Oracle function.

I wanted to implement Grover's algorithm on 4 qubits. I've been following the below Qiskit notebook: https://qiskit.org/textbook/ch-algorithms/grover.html

The part that's troubling me is the controlled Z gate and its implementation. Any help would be appreciated.

Answer 1

Some modification of the following handles most of my Grover needs.

def grover_circuit(oracle: QuantumCircuit, repeat=1):
    size = oracle.num_qubits
    circuit = QuantumCircuit(size, size)
    circuit.h(range(size))
    for _ in range(repeat):
        circuit.barrier()
        circuit &= oracle
        circuit.barrier()
        circuit.h(range(size))
        circuit.x(range(size))
        circuit.h(size - 1)
        circuit.mct(range(size - 1), size - 1)
        circuit.h(size - 1)
        circuit.x(range(size))
        circuit.h(range(size))
    circuit.measure(range(size), range(size))
    return circuit

You will have to figure out on your own how many times you'll need to repeat.