[2391] | 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) 2003-2007 |
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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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[2492] | 19 | |
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| 20 | ///\ingroup demos |
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| 21 | ///\file |
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| 22 | ///\brief Mixed integer program solver demo |
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| 23 | /// |
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| 24 | /// This example shows how can we solve an integer program with lemon |
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| 25 | /// \c Mip interface and with default solver. |
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| 26 | /// |
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| 27 | /// \include mip_demo.cc |
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| 28 | |
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[2146] | 29 | #include <lemon/lp.h> |
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| 30 | |
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| 31 | using namespace lemon; |
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| 32 | |
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| 33 | int main(){ |
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| 34 | |
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| 35 | Mip ilp; |
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| 36 | |
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[2148] | 37 | |
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[2146] | 38 | typedef Mip::Row Row; |
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| 39 | typedef Mip::Col Col; |
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| 40 | |
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| 41 | ilp.max(); |
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| 42 | |
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| 43 | Col x1 = ilp.addCol(); |
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| 44 | Col x2 = ilp.addCol(); |
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| 45 | Col x3 = ilp.addCol(); |
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| 46 | |
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| 47 | ilp.integer(x1,true); |
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| 48 | ilp.integer(x2,true); |
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| 49 | ilp.integer(x3,true); |
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| 50 | |
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| 51 | ilp.addRow(x1+x2+x3 <=100); |
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| 52 | ilp.addRow(10*x1+4*x2+5*x3<=600); |
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| 53 | ilp.addRow(2*x1+2*x2+6*x3<=300); |
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| 54 | |
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| 55 | ilp.colLowerBound(x1, 0); |
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| 56 | ilp.colLowerBound(x2, 0); |
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| 57 | ilp.colLowerBound(x3, 0); |
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| 58 | //Objective function |
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[2369] | 59 | ilp.obj(10*x1+6*x2+4*x3); |
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[2146] | 60 | |
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| 61 | //Call the routine of the underlying LP solver |
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| 62 | ilp.solve(); |
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| 63 | |
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| 64 | //Print results |
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| 65 | if (ilp.primalStatus()==LpSolverBase::OPTIMAL){ |
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| 66 | std::cout<<"Optimal solution found!"<<std::endl; |
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| 67 | printf("optimum value = %g; x1 = %g; x2 = %g; x3 = %g\n", |
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| 68 | ilp.primalValue(), |
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| 69 | ilp.primal(x1), ilp.primal(x2), ilp.primal(x3)); |
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| 70 | } |
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| 71 | else{ |
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| 72 | std::cout<<"Optimal solution not found!"<<std::endl; |
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| 73 | } |
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| 74 | |
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| 75 | } |
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