"""This module contains the ``LeapHybridSolver`` class."""
from __future__ import annotations
from typing import Any
from dwave.system import LeapHybridSampler
from tno.quantum.optimization.qubo.components import QUBO, Solver
from tno.quantum.optimization.qubo.solvers._dwave._dimod_sample_set_result import (
DimodSampleSetResult,
)
from tno.quantum.optimization.qubo.solvers._dwave._utils import (
get_singleton,
retry_on_network_errors,
)
from tno.quantum.utils.validation import check_int
[docs]class LeapHybridSolver(Solver[DimodSampleSetResult]):
"""D-Wave leap hybrid solver.
The :py:class:`LeapHybridSolver` class solves QUBOs using the quantum-classical
hybrid :py:class:`~dwave.system.samplers.LeapHybridSampler`.
Example:
>>> from tno.quantum.optimization.qubo.components import QUBO
>>> from tno.quantum.optimization.qubo.solvers import LeapHybridSolver
>>>
>>> qubo = QUBO([[1, 2, 3], [4, -50, 6], [7, 8, 9]])
>>> solver = LeapHybridSolver() # doctest: +SKIP
>>> result = solver.solve(qubo) # doctest: +SKIP
>>> result.best_bitvector # doctest: +SKIP
BitVector(010)
"""
non_deterministic = True
[docs] def __init__(self, *, num_attempts: int = 1, **sample_kwargs: Any) -> None:
"""Init :py:class:`LeapHybridSolver`.
Args:
num_attempts: Number of solve attempts whenever a
:py:exc:`~http.client.RemoteDisconnected`, or
:py:exc:`~urllib3.exceptions.ProtocolError` or
:py:exc:`~requests.ConnectionError` errors has occurred. Waits 15
seconds in between attempts.
sample_kwargs: Additional keyword arguments that can be used for the
sampler. See the D-Wave documentation of
:py:meth:`~dwave.system.samplers.LeapHybridSampler.sample` for possible
additional keyword definitions.
"""
self.sampler = get_singleton(LeapHybridSampler)
self.num_attempts = check_int(num_attempts, "num_attempts", l_bound=1)
self.sample_kwargs = sample_kwargs
@retry_on_network_errors
def _solve(self, qubo: QUBO) -> DimodSampleSetResult:
"""Solve QUBO using the quantum-classical hybrid ``LeapHybridSampler``."""
response = self.sampler.sample(qubo.to_bqm(), **self.sample_kwargs)
return DimodSampleSetResult.from_result(qubo, response)