linear_solver: Add Basic_example

ortools/linear_solver/samples/BasicExample.java

@@ -0,0 +1,71 @@
+// 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.
+
+// Minimal example to call the GLOP solver.
+// [START program]
+package com.google.ortools.linearsolver.samples;
+// [START import]
+import com.google.ortools.Loader;
+import com.google.ortools.linearsolver.MPConstraint;
+import com.google.ortools.linearsolver.MPObjective;
+import com.google.ortools.linearsolver.MPSolver;
+import com.google.ortools.linearsolver.MPVariable;
+// [END import]
+
+/** Minimal Linear Programming example to showcase calling the solver.*/
+public class SimpleLpProgram {
+  public static void main(String[] args) throws Exception {
+    Loader.loadNativeLibraries();
+    // [START solver]
+    // Create the linear solver with the GLOP backend.
+    MPSolver solver = MPSolver.createSolver("GLOP");
+    // [END solver]
+
+    // [START variables]
+    // Create the variables x and y.
+    MPVariable x = solver.makeNumVar(0.0, 1.0, "x");
+    MPVariable y = solver.makeNumVar(0.0, 2.0, "y");
+
+    System.out.println("Number of variables = " + solver.numVariables());
+    // [END variables]
+
+    // [START constraints]
+    // Create a linear constraint, 0 <= x + y <= 2.
+    MPConstraint ct = solver.makeConstraint(0.0, 2.0, "ct");
+    ct.setCoefficient(x, 1);
+    ct.setCoefficient(y, 1);
+
+    System.out.println("Number of constraints = " + solver.numConstraints());
+    // [END constraints]
+
+    // [START objective]
+    // Create the objective function, 3 * x + y.
+    MPObjective objective = solver.objective();
+    objective.setCoefficient(x, 3);
+    objective.setCoefficient(y, 1);
+    objective.setMaximization();
+    // [END objective]
+
+    // [START solve]
+    solver.solve();
+    // [END solve]
+
+    // [START print_solution]
+    System.out.println("Solution:");
+    System.out.println("Objective value = " + objective.value());
+    System.out.println("x = " + x.solutionValue());
+    System.out.println("y = " + y.solutionValue());
+    // [END print_solution]
+  }
+}
+// [END program]