def test_minimal_sequence_search_does_not_use_used():
q00 = cirq.GridQubit(0, 0)
q10 = cirq.GridQubit(1, 0)
q20 = cirq.GridQubit(2, 0)
q21 = cirq.GridQubit(2, 1)
qubits = [q00, q10, q20, q21]
search = greedy._PickFewestNeighbors(_create_device(qubits), q10)
# + *-+
#
# +
assert search._choose_next_qubit(q10, {q00, q10}) == q20
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_minimal_sequence_search_returns_none_when_blocked():
q00 = cirq.GridQubit(0, 0)
q10 = cirq.GridQubit(1, 0)
qubits = [q00, q10]
search = greedy._PickFewestNeighbors(_create_device(qubits), q10)
assert search._choose_next_qubit(q10, {q00, q10}) is None
def test_minimal_sequence_search_returns_none_for_single_node():
q00 = cirq.GridQubit(0, 0)
qubits = [q00]
search = greedy._PickFewestNeighbors(_create_device(qubits), q00)
assert search._choose_next_qubit(q00, {q00}) is None