adding basic example of mathopt for knapsack

examples/knapsack/knapsack_mathopt_solver.py

@@ -0,0 +1,32 @@
+#  Copyright (c) 2024 AIRBUS and its affiliates.
+#  This source code is licensed under the MIT license found in the
+#  LICENSE file in the root directory of this source tree.
+
+"""Playing with the new Mathopt api from ortools"""
+
+from ortools.math_opt.python import mathopt
+
+from discrete_optimization.knapsack.knapsack_parser import (
+    get_data_available,
+    parse_file,
+)
+from discrete_optimization.knapsack.solvers.lp_solvers import LPKnapsackMathOpt
+
+
+def run_mathopt_knapsack():
+    file = [f for f in get_data_available() if "ks_1000_0" in f][0]
+    knapsack_model = parse_file(file)
+    solver = LPKnapsackMathOpt(problem=knapsack_model)
+    solver.init_model()
+    res = solver.solve(
+        time_limit=30,
+        mathopt_enable_output=True,
+        mathopt_solver_type=mathopt.SolverType.GSCIP,
+    )
+    print(solver.termination)
+    sol = res.get_best_solution_fit()[0]
+    print(sol)
+
+
+if __name__ == "__main__":
+    run_mathopt_knapsack()