def test_edge_case_qubits_empty():
"""
Checks that the list of qubits to apply the grover
diffusion operator to must be non-empty
"""
with pytest.raises(AssertionError):
amplify(A, A_inv, oracle, [], iters)
def grover(oracle, qubits, num_iter=None):
"""
Implementation of Grover's Algorithm for a given oracle.
The query qubit will be left in the zero state afterwards.
:param Program oracle: An oracle defined as a Program.
It should send |x> to (-1)^f(x)|x>,
where the range of f is {0, 1}.
:param list(int) qubits: List of qubits for Grover's Algorithm.
:param int num_iter: The number of iterations to repeat the algorithm for.
The default is the integer closest to
:math:`\\frac{\\pi}{4}\sqrt{N}`, where :math:`N` is
the size of the domain.
:return: A program corresponding to
the desired instance of Grover's Algorithm.
:rtype: Program
"""
if len(qubits) < 1:
raise ValueError("Grover's Algorithm requires at least 1 qubits.")
if num_iter is None:
num_iter = int(round(np.pi * 2**(len(qubits) / 2.0 - 2.0)))
many_hadamard = pq.Program().inst(list(map(H, qubits)))
amp_prog = amp.amplify(many_hadamard, many_hadamard, oracle, qubits,
num_iter)
return amp_prog
def test_amplify_init():
"""
Test the usage of amplify without init
"""
# Essentially Grover's to select 011 or 111
desired = cz_gate + A_inv + diffusion_operator(
qubits) + A + cz_gate + A_inv + diffusion_operator(qubits) + A
created = amplify(A, A_inv, cz_gate, qubits, iters, init=False)
compare_progs(desired, created)
def test_amplify():
"""
Test the generic usage of amplify
"""
# Essentially Grover's to select 011 or 111
desired = A + cz_gate + A_inv + diffusion_operator(
qubits) + A + cz_gate + A_inv + diffusion_operator(qubits) + A
created = amplify(A, A_inv, cz_gate, qubits, iters)
compare_progs(desired, created)
def test_edge_case_amplify_0_iters():
"""
Checks that the number of iterations needed to be greater than 0
"""
with pytest.raises(AssertionError):
amplify(A, A_inv, oracle, qubits, 0)
def test_edge_case_oracle_none():
"""
Checks that U_w cannot be None
"""
with pytest.raises(AssertionError):
amplify(A, A_inv, None, qubits, iters)