Add Samples from g3

ortools/linear_solver/samples/integer_programming_example.py

@@ -0,0 +1,79 @@
+# Copyright 2010-2018 Google LLC
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Small example to illustrate solving a MIP problem."""
+# [START program]
+from __future__ import print_function
+# [START import]
+from ortools.linear_solver import pywraplp
+
+# [END import]
+
+
+def IntegerProgrammingExample():
+    """Integer programming sample."""
+    # [START solver]
+    # Create the mip solver with the CBC backend.
+    solver = pywraplp.Solver('IntegerProgrammingExample',
+                             pywraplp.Solver.CBC_MIXED_INTEGER_PROGRAMMING)
+    # [END solver]
+
+    # [START variables]
+    # x, y, and z are non-negative integer variables.
+    x = solver.IntVar(0.0, solver.infinity(), 'x')
+    y = solver.IntVar(0.0, solver.infinity(), 'y')
+    z = solver.IntVar(0.0, solver.infinity(), 'z')
+    # [END variables]
+
+    # [START constraints]
+    # 2*x + 7*y + 3*z <= 50
+    constraint0 = solver.Constraint(-solver.infinity(), 50)
+    constraint0.SetCoefficient(x, 2)
+    constraint0.SetCoefficient(y, 7)
+    constraint0.SetCoefficient(z, 3)
+
+    # 3*x - 5*y + 7*z <= 45
+    constraint1 = solver.Constraint(-solver.infinity(), 45)
+    constraint1.SetCoefficient(x, 3)
+    constraint1.SetCoefficient(y, -5)
+    constraint1.SetCoefficient(z, 7)
+
+    # 5*x + 2*y - 6*z <= 37
+    constraint2 = solver.Constraint(-solver.infinity(), 37)
+    constraint2.SetCoefficient(x, 5)
+    constraint2.SetCoefficient(y, 2)
+    constraint2.SetCoefficient(z, -6)
+    # [END constraints]
+
+    # [START objective]
+    # Maximize 2*x + 2*y + 3*z
+    objective = solver.Objective()
+    objective.SetCoefficient(x, 2)
+    objective.SetCoefficient(y, 2)
+    objective.SetCoefficient(z, 3)
+    objective.SetMaximization()
+    # [END objective]
+
+    # Solve the problem and print the solution.
+    # [START print_solution]
+    solver.Solve()
+    # Print the objective value of the solution.
+    print('Maximum objective function value = %d' % solver.Objective().Value())
+    print()
+    # Print the value of each variable in the solution.
+    for variable in [x, y, z]:
+        print('%s = %d' % (variable.name(), variable.solution_value()))
+    # [END print_solution]
+
+
+IntegerProgrammingExample()
+# [END program]