Source code for tno.quantum.optimization.qubo.solvers._dwave._exact_sampler_solver

"""This module contains the ``ExactSamplerSolver`` class."""

from __future__ import annotations

from typing import Any

from dimod import ExactSolver

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,
)


[docs]class ExactSamplerSolver(Solver[DimodSampleSetResult]): """D-Wave exact sampler solver. The :py:class:`ExactSamplerSolver` class solves QUBOs exactly using a brute force search by the :py:class:`~dimod.reference.samplers.ExactSolver`. Example: >>> from tno.quantum.optimization.qubo.components import QUBO >>> from tno.quantum.optimization.qubo.solvers import ExactSamplerSolver >>> >>> qubo = QUBO([[1, 2, 3], [4, -50, 6], [7, 8, 9]]) >>> solver = ExactSamplerSolver() >>> result = solver.solve(qubo) >>> result.best_bitvector BitVector(010) """
[docs] def __init__(self, **sample_kwargs: Any) -> None: """Init :py:class:`ExactSamplerSolver`. Args: sample_kwargs: Additional keyword arguments that can be used for the sampler. The :py:class:`~dimod.reference.samplers.ExactSolver` does not take additional parameters. """ self.sampler = get_singleton(ExactSolver) self.sample_kwargs = sample_kwargs
def _solve(self, qubo: QUBO) -> DimodSampleSetResult: """Solves the given QUBO using sample_qubo functionality of the ExactSolver.""" response = self.sampler.sample(qubo.to_bqm(), **self.sample_kwargs) return DimodSampleSetResult.from_result(qubo, response)