95 lines
3.0 KiB
C#
95 lines
3.0 KiB
C#
// Copyright 2012 Hakan Kjellerstrand
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//
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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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using System;
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using System.Collections;
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using System.Collections.Generic;
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using System.Linq;
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using Google.OrTools.LinearSolver;
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public class Volsay2
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{
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/**
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* Volsay problem.
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*
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* From the OPL model volsay.mod.
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*
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* Also see
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* http://www.hakank.org/or-tools/volsay.cs
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* http://www.hakank.org/or-tools/volsay2.py
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*/
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private static void Solve()
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{
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Solver solver = Solver.CreateSolver("CLP");
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if (solver is null)
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{
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return;
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}
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int num_products = 2;
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IEnumerable<int> PRODUCTS = Enumerable.Range(0, num_products);
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int Gas = 0;
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int Chloride = 1;
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String[] products = { "Gas", "Chloride" };
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//
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// Variables
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//
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Variable[] production = new Variable[num_products];
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foreach (int p in PRODUCTS)
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{
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production[p] = solver.MakeNumVar(0, 100000, products[p]);
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}
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int num_constraints = 2;
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IEnumerable<int> CONSTRAINTS = Enumerable.Range(0, num_constraints);
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Constraint[] cons = new Constraint[num_constraints];
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cons[0] = solver.Add(production[Gas] + production[Chloride] <= 50);
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cons[1] = solver.Add(3 * production[Gas] + 4 * production[Chloride] <= 180);
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solver.Maximize(40 * production[Gas] + 50 * production[Chloride]);
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Console.WriteLine("NumConstraints: {0}", solver.NumConstraints());
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Solver.ResultStatus resultStatus = solver.Solve();
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if (resultStatus != Solver.ResultStatus.OPTIMAL)
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{
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Console.WriteLine("The problem don't have an optimal solution.");
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return;
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}
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foreach (int p in PRODUCTS)
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{
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Console.WriteLine("{0,-10}: {1} ReducedCost: {2}", products[p], production[p].SolutionValue(),
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production[p].ReducedCost());
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}
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double[] activities = solver.ComputeConstraintActivities();
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foreach (int c in CONSTRAINTS)
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{
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Console.WriteLine("Constraint {0} DualValue {1} Activity: {2} lb: {3} ub: {4}", c.ToString(),
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cons[c].DualValue(), activities[cons[c].Index()], cons[c].Lb(), cons[c].Ub());
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}
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Console.WriteLine("\nWallTime: " + solver.WallTime());
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Console.WriteLine("Iterations: " + solver.Iterations());
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}
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public static void Main(String[] args)
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{
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Solve();
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}
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}
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