def test_greedy_search_method_calls_all():
q00 = cirq.GridQubit(0, 0)
q01 = cirq.GridQubit(0, 1)
qubits = [q00, q01]
length = 2
method = greedy.GreedySequenceSearchStrategy()
assert len(method.place_line(_create_device(qubits), length)) == 2
def test_largest_sequence_search_traverses_grid():
q00 = cirq.GridQubit(0, 0)
q10 = cirq.GridQubit(1, 0)
q11 = cirq.GridQubit(1, 1)
q20 = cirq.GridQubit(2, 0)
q30 = cirq.GridQubit(3, 0)
q40 = cirq.GridQubit(4, 0)
q41 = cirq.GridQubit(4, 1)
q42 = cirq.GridQubit(4, 2)
q50 = cirq.GridQubit(5, 0)
qubits = [q00, q10, q11, q20, q30, q40, q50, q41, q42]
device = _create_device(qubits)
search = greedy._PickLargestArea(device, q20)
# + + +-+-+ +
# |
# + +
# |
# +
assert search._choose_next_qubit(q20, {q20}) == q30
assert search._choose_next_qubit(q30, {q20, q30}) == q40
assert search._choose_next_qubit(q40, {q20, q30, q40}) == q41
assert search._choose_next_qubit(q41, {q20, q30, q40, q41}) == q42
assert search._choose_next_qubit(q42, {q20, q30, q40, q41, q42}) is None
method = greedy.GreedySequenceSearchStrategy('largest_area')
assert method.place_line(device, 7) == GridQubitLineTuple(
[q00, q10, q20, q30, q40, q41, q42])
with pytest.raises(NotFoundError):
_ = method.place_line(device, 8)
def test_greedy_search_method_returns_longest():
q00 = cirq.GridQubit(0, 0)
q10 = cirq.GridQubit(1, 0)
device = _create_device([q00, q10])
length = 1
method = greedy.GreedySequenceSearchStrategy()
assert method.place_line(device, length) == GridQubitLineTuple([q00])
def test_greedy_search_method_fails_when_unknown():
q00 = cirq.GridQubit(0, 0)
q01 = cirq.GridQubit(0, 1)
qubits = [q00, q01]
length = 2
method = greedy.GreedySequenceSearchStrategy('fail')
with pytest.raises(ValueError):
method.place_line(_create_device(qubits), length)
def test_minimal_sequence_search_traverses_grid():
q00 = cirq.GridQubit(0, 0)
q01 = cirq.GridQubit(0, 1)
q11 = cirq.GridQubit(1, 1)
q02 = cirq.GridQubit(0, 2)
q03 = cirq.GridQubit(0, 3)
q04 = cirq.GridQubit(0, 4)
q14 = cirq.GridQubit(1, 4)
q24 = cirq.GridQubit(2, 4)
q05 = cirq.GridQubit(0, 5)
qubits = [q00, q01, q11, q02, q03, q04, q05, q14, q24]
device = _create_device(qubits)
search = greedy._PickFewestNeighbors(device, q02)
# (0,0)╌╌(0,1)╌╌START══(0,3)══(0,4)╌╌(0,5)
# ╎ ║
# (1,1) (1,4)
# ║
# (2,4)
assert search._choose_next_qubit(q02, {q02}) == q03
assert search._choose_next_qubit(q03, {q02, q03}) == q04
assert search._choose_next_qubit(q04, {q02, q03, q04}) == q14
assert search._choose_next_qubit(q14, {q02, q03, q04, q14}) == q24
assert search._choose_next_qubit(q24, {q02, q03, q04, q14, q24}) is None
# (0,0)╌╌(0,1)══(0,2)══(0,3)══(0,4)╌╌(0,5)
# ║ ║
# (1,1) (1,4)
# ║
# START
assert search._choose_next_qubit(q24, {q24}) == q14
assert search._choose_next_qubit(q14, {q24, q14}) == q04
assert search._choose_next_qubit(q04, {q24, q14, q04}) == q03
assert search._choose_next_qubit(q03, {q24, q14, q04, q03}) == q02
assert search._choose_next_qubit(q02, {q24, q14, q04, q03, q02}) == q01
assert search._choose_next_qubit(
q01, {q24, q14, q04, q03, q02, q01}) in [q00, q11]
assert search._choose_next_qubit(
q00, {q24, q14, q04, q03, q02, q01, q00}) is None
assert search._choose_next_qubit(
q11, {q24, q14, q04, q03, q02, q01, q11}) is None
# START══(0,1)══(0,2)══(0,3)══(0,4)╌╌(0,5)
# ║
# (1,4)
# ║
# (2,4)
qubits = [q00, q01, q02, q03, q04, q05, q14, q24]
device = _create_device(qubits)
method = greedy.GreedySequenceSearchStrategy('minimal_connectivity')
assert method.place_line(device, 4) == (q00, q01, q02, q03)
assert method.place_line(device, 7) == (q00, q01, q02, q03, q04, q14, q24)
with pytest.raises(NotFoundError):
_ = method.place_line(device, 8)
def test_greedy_search_method_calls_minimal_only(minimal, largest):
q00 = cirq.GridQubit(0, 0)
q01 = cirq.GridQubit(0, 1)
device = _create_device([q00, q01])
length = 2
sequence = [q00, q01]
minimal.return_value.get_or_search.return_value = sequence
method = greedy.GreedySequenceSearchStrategy('minimal_connectivity')
assert method.place_line(device, length) == GridQubitLineTuple(sequence)
largest.return_value.get_or_search.assert_not_called()
minimal.return_value.get_or_search.assert_called_once_with()
def line_on_device(
device: 'cirq_google.GridDevice',
length: int,
method: LinePlacementStrategy = greedy.GreedySequenceSearchStrategy(),
) -> GridQubitLineTuple:
"""Searches for linear sequence of qubits on device.
Args:
device: Google Xmon device instance.
length: Desired number of qubits making up the line.
method: Line placement method. Defaults to
cirq.greedy.GreedySequenceSearchMethod.
Returns:
Line sequences search results.
"""
return method.place_line(device, length)
def test_greedy_search_method_returns_empty_when_empty():
device = _create_device([])
length = 0
method = greedy.GreedySequenceSearchStrategy()
assert method.place_line(device, length) == GridQubitLineTuple()
