// 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]
using System;
using Google.OrTools.LinearSolver;

public class SimpleLpProgram
{
  static void Main()
  {
    // [START solver]
    // Create the linear solver with the GLOP backend.
    Solver solver = Solver.CreateSolver("SimpleLpProgram", "GLOP");
    // [END solver]

    // [START variables]
    // Create the variables x and y.
    Variable x = solver.MakeNumVar(0.0, 1.0, "x");
    Variable y = solver.MakeNumVar(0.0, 2.0, "y");

    Console.WriteLine("Number of variables = " + solver.NumVariables());
    // [END variables]

    // [START constraints]
    // Create a linear constraint, 0 <= x + y <= 2.
    Constraint ct = solver.MakeConstraint(0.0, 2.0, "ct");
    ct.SetCoefficient(x, 1);
    ct.SetCoefficient(y, 1);

    Console.WriteLine("Number of constraints = " + solver.NumConstraints());
    // [END constraints]

    // [START objective]
    // Create the objective function, 3 * x + y.
    Objective objective = solver.Objective();
    objective.SetCoefficient(x, 3);
    objective.SetCoefficient(y, 1);
    objective.SetMaximization();
    // [END objective]

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

    // [START print_solution]
    Console.WriteLine("Solution:");
    Console.WriteLine("Objective value = " + solver.Objective().Value());
    Console.WriteLine("x = " + x.SolutionValue());
    Console.WriteLine("y = " + y.SolutionValue());
    // [END print_solution]
  }
}
// [END program]