LinearProgrammingExample.cs 2.49 KB
Newer Older
Valentin Platzgummer's avatar
Valentin Platzgummer committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
// 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.

// [START program]
using System;
using Google.OrTools.LinearSolver;

public class LinearProgrammingExample
{
  static void Main()
  {
      // [START solver]
23
      Solver solver = Solver.CreateSolver("LinearProgrammingExample", "GLOP");
Valentin Platzgummer's avatar
Valentin Platzgummer committed
24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73
      // [END solver]
      // x and y are continuous non-negative variables.
      // [START variables]
      Variable x = solver.MakeNumVar(0.0, double.PositiveInfinity, "x");
      Variable y = solver.MakeNumVar(0.0, double.PositiveInfinity, "y");
      // [END variables]

      // [START constraints]
      // x + 2y <= 14.
      Constraint c0 = solver.MakeConstraint(double.NegativeInfinity, 14.0);
      c0.SetCoefficient(x, 1);
      c0.SetCoefficient(y, 2);

      // 3x - y >= 0.
      Constraint c1 = solver.MakeConstraint(0.0, double.PositiveInfinity);
      c1.SetCoefficient(x, 3);
      c1.SetCoefficient(y, -1);

      // x - y <= 2.
      Constraint c2 = solver.MakeConstraint(double.NegativeInfinity, 2.0);
      c2.SetCoefficient(x, 1);
      c2.SetCoefficient(y, -1);
      // [END constraints]

      // [START objective]
      // Objective function: 3x + 4y.
      Objective objective = solver.Objective();
      objective.SetCoefficient(x, 3);
      objective.SetCoefficient(y, 4);
      objective.SetMaximization();
      // [END objective]

      // [START solve]
      solver.Solve();
      // [END solve]

      // [START print_solution]
      Console.WriteLine("Number of variables = " + solver.NumVariables());
      Console.WriteLine("Number of constraints = " + solver.NumConstraints());
      // The value of each variable in the solution.
      Console.WriteLine("Solution:");
      Console.WriteLine("x = " + x.SolutionValue());
      Console.WriteLine("y = " + y.SolutionValue());
      // The objective value of the solution.
      Console.WriteLine("Optimal objective value = " +
                      solver.Objective().Value());
      // [END print_solution]
    }
}
// [END program]