// 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] // [START import] using System; using Google.OrTools.LinearSolver; // [END import] // [START program_part1] public class MipVarArray { // [START data_model] class DataModel { public double[,] ConstraintCoeffs = { {5, 7, 9, 2, 1}, {18, 4, -9, 10, 12}, {4, 7, 3, 8, 5}, {5, 13, 16, 3, -7}, }; public double[] Bounds = { 250, 285, 211, 315 }; public double[] ObjCoeffs = { 7, 8, 2, 9, 6 }; public int NumVars = 5; public int NumConstraints = 4; } // [END data_model] public static void Main() { // [START data] DataModel data = new DataModel(); // [END data] // [END program_part1] // [START solver] // Create the linear solver with the CBC backend. Solver solver = Solver.CreateSolver("SimpleMipProgram", "CBC_MIXED_INTEGER_PROGRAMMING"); // [END solver] // [START program_part2] // [START variables] Variable[] x = new Variable[data.NumVars]; for (int j = 0; j < data.NumVars; j++) { x[j] = solver.MakeIntVar(0.0, double.PositiveInfinity, $"x_{j}"); } Console.WriteLine("Number of variables = " + solver.NumVariables()); // [END variables] // [START constraints] for (int i = 0; i < data.NumConstraints; ++i) { Constraint constraint = solver.MakeConstraint(0, data.Bounds[i], ""); for (int j = 0; j < data.NumVars; ++j) { constraint.SetCoefficient(x[j], data.ConstraintCoeffs[i, j]); } } Console.WriteLine("Number of constraints = " + solver.NumConstraints()); // [END constraints] // [START objective] Objective objective = solver.Objective(); for (int j = 0; j < data.NumVars; ++j) { objective.SetCoefficient(x[j], data.ObjCoeffs[j]); } objective.SetMaximization(); // [END objective] // [START solve] Solver.ResultStatus resultStatus = solver.Solve(); // [END solve] // [START print_solution] // Check that the problem has an optimal solution. if (resultStatus != Solver.ResultStatus.OPTIMAL) { Console.WriteLine("The problem does not have an optimal solution!"); return; } Console.WriteLine("Solution:"); Console.WriteLine("Optimal objective value = " + solver.Objective().Value()); for (int j = 0; j < data.NumVars; ++j) { Console.WriteLine("x[" + j + "] = " + x[j].SolutionValue()); } // [END print_solution] // [START advanced] Console.WriteLine("\nAdvanced usage:"); Console.WriteLine("Problem solved in " + solver.WallTime() + " milliseconds"); Console.WriteLine("Problem solved in " + solver.Iterations() + " iterations"); Console.WriteLine("Problem solved in " + solver.Nodes() + " branch-and-bound nodes"); // [END advanced] } } // [END program_part2] // [END program]