119 lines
3.1 KiB
C#
119 lines
3.1 KiB
C#
//
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// 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 Volsay3
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{
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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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* This version use arrays and matrices
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*
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*
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* Also see
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* http://www.hakank.org/or-tools/volsay2.cs
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* http://www.hakank.org/or-tools/volsay3.py
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*
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*/
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private static void Solve()
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{
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Solver solver = new Solver("Volsay3",
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Solver.CLP_LINEAR_PROGRAMMING);
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int num_products = 2;
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IEnumerable<int> PRODUCTS = Enumerable.Range(0, num_products);
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String[] products = {"Gas", "Chloride"};
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String[] components = {"nitrogen", "hydrogen", "chlorine"};
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int[,] demand = { {1,3,0}, {1,4,1}};
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int[] profit = {30,40};
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int[] stock = {50,180,40};
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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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production[p] = solver.MakeNumVar(0, 100000, products[p]);
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}
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//
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// Constraints
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//
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int c_len = components.Length;
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Constraint[] cons = new Constraint[c_len];
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for(int c = 0; c < c_len; c++) {
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cons[c] = solver.Add( (from p in PRODUCTS
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select (demand[p,c]*production[p])).
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ToArray().Sum() <= stock[c]);
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}
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//
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// Objective
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//
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solver.Maximize( (from p in PRODUCTS
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select (profit[p]*production[p])).
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ToArray().Sum()
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);
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if (solver.Solve() != Solver.OPTIMAL) {
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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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Console.WriteLine("Objective: {0}", solver.Objective().Value());
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foreach(int p in PRODUCTS) {
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Console.WriteLine("{0,-10}: {1} ReducedCost: {2}",
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products[p],
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production[p].SolutionValue(),
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production[p].ReducedCost());
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}
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for(int c = 0; c < c_len; c++) {
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Console.WriteLine("Constraint {0} DualValue {1} Activity: {2} lb: {3} ub: {4}",
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c,
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cons[c].DualValue(),
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cons[c].Activity(),
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cons[c].Lb(),
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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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