78 lines
2.5 KiB
C#
78 lines
2.5 KiB
C#
// Copyright 2010-2018 Google LLC
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// [START program]
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// [START import]
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using System;
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using Google.OrTools.LinearSolver;
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// [END import]
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public class SimpleMipProgram
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{
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static void Main()
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{
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// [START solver]
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// Create the linear solver with the CBC backend.
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Solver solver = Solver.CreateSolver("SimpleMipProgram", "CBC_MIXED_INTEGER_PROGRAMMING");
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// [END solver]
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// [START variables]
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// x and y are integer non-negative variables.
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Variable x = solver.MakeIntVar(0.0, double.PositiveInfinity, "x");
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Variable y = solver.MakeIntVar(0.0, double.PositiveInfinity, "y");
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Console.WriteLine("Number of variables = " + solver.NumVariables());
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// [END variables]
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// [START constraints]
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// x + 7 * y <= 17.5.
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solver.Add(x + 7 * y <= 17.5);
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// x <= 3.5.
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solver.Add(x <= 3.5);
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Console.WriteLine("Number of constraints = " + solver.NumConstraints());
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// [END constraints]
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// [START objective]
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// Maximize x + 10 * y.
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solver.Maximize(x + 10 * y);
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// [END objective]
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// [START solve]
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Solver.ResultStatus resultStatus = solver.Solve();
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// Check that the problem has an optimal solution.
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if (resultStatus != Solver.ResultStatus.OPTIMAL)
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{
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Console.WriteLine("The problem does not have an optimal solution!");
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return;
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}
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// [END solve]
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// [START print_solution]
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Console.WriteLine("Solution:");
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Console.WriteLine("Objective value = " + solver.Objective().Value());
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Console.WriteLine("x = " + x.SolutionValue());
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Console.WriteLine("y = " + y.SolutionValue());
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// [END print_solution]
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// [START advanced]
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Console.WriteLine("\nAdvanced usage:");
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Console.WriteLine("Problem solved in " + solver.WallTime() + " milliseconds");
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Console.WriteLine("Problem solved in " + solver.Iterations() + " iterations");
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Console.WriteLine("Problem solved in " + solver.Nodes() + " branch-and-bound nodes");
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// [END advanced]
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}
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}
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// [END program]
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