Fix bug in max-cut solver (issue #611) (backport #635)

.pylintrc

@@ -71,6 +71,7 @@ disable=fixme,              # disabled as TODOs would show up as warnings
     no-else-return,     # relax "elif" after a clause with a return
     docstring-first-line-empty, # relax docstring style
     import-outside-toplevel,
+    unknown-option-value,
 
 
 [REPORTS]

qiskit_optimization/algorithms/admm_optimizer.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2020, 2023.
+# (C) Copyright IBM 2020, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -42,7 +42,7 @@
 class ADMMParameters:
     """Defines a set of parameters for ADMM optimizer."""
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         rho_initial: float = 10000,
         factor_c: float = 100000,
@@ -175,7 +175,7 @@ def __init__(self, op: QuadraticProgram, rho_initial: float) -> None:
 class ADMMOptimizationResult(OptimizationResult):
     """ADMMOptimization Result."""
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         x: np.ndarray,
         fval: float,

qiskit_optimization/algorithms/cobyla_optimizer.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2020, 2023.
+# (C) Copyright IBM 2020, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -43,7 +43,7 @@ class CobylaOptimizer(MultiStartOptimizer):
         >>> result = optimizer.solve(problem)
     """
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         rhobeg: float = 1.0,
         rhoend: float = 1e-4,

qiskit_optimization/algorithms/goemans_williamson_optimizer.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2021, 2023.
+# (C) Copyright IBM 2021, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -39,7 +39,7 @@ class GoemansWilliamsonOptimizationResult(OptimizationResult):
     values of just one solution. Explore ``samples`` for all possible solutions.
     """
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         x: Optional[Union[List[float], np.ndarray]],
         fval: float,

qiskit_optimization/algorithms/grover_optimizer.py

@@ -41,7 +41,7 @@
 class GroverOptimizer(OptimizationAlgorithm):
     """Uses Grover Adaptive Search (GAS) to find the minimum of a QUBO function."""
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         num_value_qubits: int,
         num_iterations: int = 3,
@@ -325,7 +325,7 @@ def _bin_to_int(v: str, num_value_bits: int) -> int:
 class GroverOptimizationResult(OptimizationResult):
     """A result object for Grover Optimization methods."""
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         x: Union[List[float], np.ndarray],
         fval: float,

qiskit_optimization/algorithms/minimum_eigen_optimizer.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2020, 2023.
+# (C) Copyright IBM 2020, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -39,7 +39,7 @@
 class MinimumEigenOptimizationResult(OptimizationResult):
     """Minimum Eigen Optimizer Result."""
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         x: Optional[Union[List[float], np.ndarray]],
         fval: Optional[float],

qiskit_optimization/algorithms/optimization_algorithm.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2020, 2023.
+# (C) Copyright IBM 2020, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -97,7 +97,7 @@ class OptimizationResult:
         should maintain the order when generating a new ``OptimizationResult`` object.
     """
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         x: Union[List[float], np.ndarray] | None,
         fval: float | None,

qiskit_optimization/algorithms/recursive_minimum_eigen_optimizer.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2020, 2023.
+# (C) Copyright IBM 2020, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -52,7 +52,7 @@ class IntermediateResult(Enum):
 class RecursiveMinimumEigenOptimizationResult(OptimizationResult):
     """Recursive Eigen Optimizer Result."""
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         x: Union[List[float], np.ndarray],
         fval: float,
@@ -137,7 +137,7 @@ class RecursiveMinimumEigenOptimizer(OptimizationAlgorithm):
         from Symmetry Protection. `arXiv:1910.08980 <http://arxiv.org/abs/1910.08980>`_
     """
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         optimizer: OptimizationAlgorithm,
         min_num_vars: int = 1,

qiskit_optimization/algorithms/slsqp_optimizer.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2020, 2023.
+# (C) Copyright IBM 2020, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -30,7 +30,7 @@ class SlsqpOptimizationResult(OptimizationResult):
     SLSQP optimization result, defines additional properties that may be returned by the optimizer.
     """
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         x: Union[List[float], np.ndarray],
         fval: float,
@@ -104,7 +104,7 @@ class SlsqpOptimizer(MultiStartOptimizer):
     """
 
     # pylint: disable=redefined-builtin
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         iter: int = 100,
         acc: float = 1.0e-6,

qiskit_optimization/algorithms/warm_start_qaoa_optimizer.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2021, 2023.
+# (C) Copyright IBM 2021, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -198,7 +198,7 @@ class WarmStartQAOAOptimizer(MinimumEigenOptimizer):
 
     """
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         pre_solver: OptimizationAlgorithm,
         relax_for_pre_solver: bool,

qiskit_optimization/applications/max_cut.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2018, 2023.
+# (C) Copyright IBM 2018, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -114,10 +114,10 @@ def parse_gset_format(filename: str) -> np.ndarray:
                     w = np.zeros((n, n))
                     header = False
                 else:
-                    s__, t__, _ = v
+                    s__, t__, w__ = v
                     s__ -= 1  # adjust 1-index
                     t__ -= 1  # ditto
-                    w[s__, t__] = t__
+                    w[s__, t__] = w__
                     count += 1
             assert m == count
         w += w.T

qiskit_optimization/applications/vehicle_routing.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2018, 2023.
+# (C) Copyright IBM 2018, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -217,7 +217,7 @@ def depot(self, depot: int) -> None:
 
     @staticmethod
     # pylint: disable=undefined-variable
-    def create_random_instance(
+    def create_random_instance(  # pylint: disable=too-many-positional-arguments
         n: int,
         low: int = 0,
         high: int = 100,

qiskit_optimization/problems/linear_constraint.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2019, 2023.
+# (C) Copyright IBM 2019, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -27,7 +27,7 @@ class LinearConstraint(Constraint):
     # Note: added, duplicating in effect that in Constraint, to avoid issues with Sphinx
     Sense = ConstraintSense
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         quadratic_program: Any,
         name: str,

qiskit_optimization/problems/quadratic_constraint.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2019, 2023.
+# (C) Copyright IBM 2019, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -28,7 +28,7 @@ class QuadraticConstraint(Constraint):
     # Note: added, duplicating in effect that in Constraint, to avoid issues with Sphinx
     Sense = ConstraintSense
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         quadratic_program: Any,
         name: str,

qiskit_optimization/problems/quadratic_objective.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2019, 2023.
+# (C) Copyright IBM 2019, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -38,7 +38,7 @@ class QuadraticObjective(QuadraticProgramElement):
 
     Sense = ObjSense
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         quadratic_program: Any,
         constant: float = 0.0,

qiskit_optimization/problems/quadratic_program.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2019, 2023.
+# (C) Copyright IBM 2019, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -185,7 +185,7 @@ def _add_variable(
             key_format = ""
         return self._add_variables(1, lowerbound, upperbound, vartype, name, key_format)[1][0]
 
-    def _add_variables(
+    def _add_variables(  # pylint: disable=too-many-positional-arguments
         self,
         keys: Union[int, Sequence],
         lowerbound: Union[float, int],
@@ -239,7 +239,7 @@ def _find_name(name, key_format, k):
             variables.append(variable)
         return names, variables
 
-    def _var_dict(
+    def _var_dict(  # pylint: disable=too-many-positional-arguments
         self,
         keys: Union[int, Sequence],
         lowerbound: Union[float, int],
@@ -277,7 +277,7 @@ def _var_dict(
             zip(*self._add_variables(keys, lowerbound, upperbound, vartype, name, key_format))
         )
 
-    def _var_list(
+    def _var_list(  # pylint: disable=too-many-positional-arguments
         self,
         keys: Union[int, Sequence],
         lowerbound: Union[float, int],
@@ -333,7 +333,7 @@ def continuous_var(
         """
         return self._add_variable(lowerbound, upperbound, Variable.Type.CONTINUOUS, name)
 
-    def continuous_var_dict(
+    def continuous_var_dict(  # pylint: disable=too-many-positional-arguments
         self,
         keys: Union[int, Sequence],
         lowerbound: Union[float, int] = 0,
@@ -367,7 +367,7 @@ def continuous_var_dict(
             keys, lowerbound, upperbound, Variable.Type.CONTINUOUS, name, key_format
         )
 
-    def continuous_var_list(
+    def continuous_var_list(  # pylint: disable=too-many-positional-arguments
         self,
         keys: Union[int, Sequence],
         lowerbound: Union[float, int] = 0,
@@ -494,7 +494,7 @@ def integer_var(
         """
         return self._add_variable(lowerbound, upperbound, Variable.Type.INTEGER, name)
 
-    def integer_var_dict(
+    def integer_var_dict(  # pylint: disable=too-many-positional-arguments
         self,
         keys: Union[int, Sequence],
         lowerbound: Union[float, int] = 0,
@@ -526,7 +526,7 @@ def integer_var_dict(
         """
         return self._var_dict(keys, lowerbound, upperbound, Variable.Type.INTEGER, name, key_format)
 
-    def integer_var_list(
+    def integer_var_list(  # pylint: disable=too-many-positional-arguments
         self,
         keys: Union[int, Sequence],
         lowerbound: Union[float, int] = 0,
@@ -717,7 +717,7 @@ def quadratic_constraints_index(self) -> Dict[str, int]:
         """
         return self._quadratic_constraints_index
 
-    def quadratic_constraint(
+    def quadratic_constraint(  # pylint: disable=too-many-positional-arguments
         self,
         linear: Union[ndarray, spmatrix, List[float], Dict[Union[int, str], float]] = None,
         quadratic: Union[

qiskit_optimization/problems/variable.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2019, 2023.
+# (C) Copyright IBM 2019, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -33,7 +33,7 @@ class Variable(QuadraticProgramElement):
 
     Type = VarType
 
-    def __init__(
+    def __init__(  # pylint: disable=too-many-positional-arguments
         self,
         quadratic_program: Any,
         name: str,

qiskit_optimization/translators/prettyprint.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2022, 2023.
+# (C) Copyright IBM 2022, 2024.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -117,7 +117,7 @@ def _concatenate_terms(terms: List[str], wrap: int, indent: int) -> str:
     return buf
 
 
-def expr2str(
+def expr2str(  # pylint: disable=too-many-positional-arguments
     constant: float = 0.0,
     linear: Optional[LinearExpression] = None,
     quadratic: Optional[QuadraticExpression] = None,