1 | /* -*- C++ -*- |
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2 | * |
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3 | * This file is a part of LEMON, a generic C++ optimization library |
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4 | * |
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5 | * Copyright (C) 2003-2008 |
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6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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8 | * |
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9 | * Permission to use, modify and distribute this software is granted |
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10 | * provided that this copyright notice appears in all copies. For |
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11 | * precise terms see the accompanying LICENSE file. |
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12 | * |
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13 | * This software is provided "AS IS" with no warranty of any kind, |
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14 | * express or implied, and with no claim as to its suitability for any |
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15 | * purpose. |
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16 | * |
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17 | */ |
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18 | |
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19 | ///\ingroup demos |
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20 | ///\file |
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21 | ///\brief Mixed integer program solver demo |
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22 | /// |
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23 | /// This example shows how can we solve an integer program with lemon |
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24 | /// \c Mip interface and with default solver. |
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25 | /// |
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26 | /// \include mip_demo.cc |
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27 | |
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28 | #include <lemon/lp.h> |
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29 | |
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30 | using namespace lemon; |
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31 | |
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32 | int main(){ |
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33 | |
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34 | Mip ilp; |
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35 | |
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36 | |
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37 | typedef Mip::Row Row; |
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38 | typedef Mip::Col Col; |
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39 | |
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40 | ilp.max(); |
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41 | |
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42 | Col x1 = ilp.addCol(); |
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43 | Col x2 = ilp.addCol(); |
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44 | Col x3 = ilp.addCol(); |
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45 | |
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46 | ilp.integer(x1,true); |
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47 | ilp.integer(x2,true); |
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48 | ilp.integer(x3,true); |
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49 | |
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50 | ilp.addRow(x1+x2+x3 <=100); |
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51 | ilp.addRow(10*x1+4*x2+5*x3<=600); |
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52 | ilp.addRow(2*x1+2*x2+6*x3<=300); |
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53 | |
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54 | ilp.colLowerBound(x1, 0); |
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55 | ilp.colLowerBound(x2, 0); |
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56 | ilp.colLowerBound(x3, 0); |
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57 | //Objective function |
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58 | ilp.obj(10*x1+6*x2+4*x3); |
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59 | |
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60 | //Call the routine of the underlying LP solver |
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61 | ilp.solve(); |
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62 | |
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63 | //Print results |
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64 | if (ilp.primalStatus()==LpSolverBase::OPTIMAL){ |
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65 | std::cout<<"Optimal solution found!"<<std::endl; |
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66 | printf("optimum value = %g; x1 = %g; x2 = %g; x3 = %g\n", |
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67 | ilp.primalValue(), |
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68 | ilp.primal(x1), ilp.primal(x2), ilp.primal(x3)); |
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69 | } |
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70 | else{ |
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71 | std::cout<<"Optimal solution not found!"<<std::endl; |
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72 | } |
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73 | |
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74 | } |
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