[1574] | 1 | // $Id: simpleBAB.cpp 1902 2013-04-10 16:58:16Z stefan $ |
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[1140] | 2 | // Copyright (C) 2009, International Business Machines |
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| 3 | // Corporation and others. All Rights Reserved. |
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[1574] | 4 | // This code is licensed under the terms of the Eclipse Public License (EPL). |
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| 5 | |
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[1140] | 6 | #include <cassert> |
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| 7 | #include <iomanip> |
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| 8 | |
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| 9 | |
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[1902] | 10 | #include "CoinPragma.hpp" |
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[1140] | 11 | #include "OsiClpSolverInterface.hpp" |
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| 12 | #include "CoinPackedVector.hpp" |
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| 13 | //#define USE_CBC |
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| 14 | #ifdef USE_CBC |
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| 15 | #include "CbcModel.hpp" |
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| 16 | #endif |
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| 17 | |
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| 18 | int main (int argc, const char *argv[]) |
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| 19 | { |
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| 20 | |
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| 21 | OsiClpSolverInterface model; |
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| 22 | |
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| 23 | int start[] = { 0, 1, 2}; |
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| 24 | int index[] = { 0, 0}; |
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| 25 | double values[] = {1.0, 2.0}; |
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| 26 | double collb[] = {0.0, 0.0}; |
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| 27 | double colub[] = {10.0, 10.0}; |
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| 28 | double obj[] = { 1.0, 1.0}; |
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| 29 | double rowlb[] = { 0.0}; |
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| 30 | double rowub[]= { 3.9}; |
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| 31 | |
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| 32 | // obj: Max x0 + x1 |
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| 33 | // st. x0 + 2 x1 <= 3.9 |
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| 34 | // 0 <= x0 <= 10 and integer |
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| 35 | // 0 <= x1 <= 10 |
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| 36 | model.loadProblem(2, 1, start, index, values, collb, colub, obj, rowlb, rowub); |
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| 37 | model.setInteger(0); |
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| 38 | model.setObjSense(-1.0); |
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[1902] | 39 | //bool optimal; |
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[1140] | 40 | |
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| 41 | #ifndef USE_CBC |
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| 42 | // Save bounds - that and dual limit should be all that is needed |
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| 43 | // For this simple example we could just re-use collb and colub |
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| 44 | double saveLower[2]; |
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| 45 | double saveUpper[2]; |
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| 46 | int numberColumns = model.getNumCols(); |
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| 47 | CoinCopyN(model.getColLower(),numberColumns,saveLower); |
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| 48 | CoinCopyN(model.getColUpper(),numberColumns,saveUpper); |
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| 49 | double objLimit; |
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| 50 | model.getDblParam(OsiDualObjectiveLimit,objLimit); |
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| 51 | model.branchAndBound(); |
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[1902] | 52 | //optimal = model.isProvenOptimal(); |
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[1140] | 53 | const double *val = model.getColSolution(); // x0 = 3, x1 = 0.45 |
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| 54 | printf("Solution %g %g\n",val[0],val[1]); |
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| 55 | // Restore bounds and dual limit |
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| 56 | model.setColLower(saveLower); |
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| 57 | model.setColUpper(saveUpper); |
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| 58 | model.setDblParam(OsiDualObjectiveLimit,objLimit); |
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| 59 | #else |
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| 60 | { |
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| 61 | CbcModel model2(model); |
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| 62 | model2.branchAndBound(); |
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[1902] | 63 | //optimal = model2.isProvenOptimal(); |
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[1140] | 64 | const double *val = model2.getColSolution(); // x0 = 3, x1 = 0.45 |
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| 65 | printf("Solution %g %g\n",val[0],val[1]); |
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| 66 | } |
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| 67 | #endif |
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| 68 | |
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| 69 | const int rowCols[] = {0}; |
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| 70 | const double rowElements = { 1.0}; |
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| 71 | |
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| 72 | // add x0 <= 2, and solve once again. |
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| 73 | CoinPackedVector v(1, rowCols, rowElements); |
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| 74 | model.addRow(v, 0.0, 2.0); |
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| 75 | #ifndef USE_CBC |
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| 76 | model.branchAndBound(); |
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[1902] | 77 | //optimal = model.isProvenOptimal(); // should be x0 = 2, x1 = 0.95 |
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[1140] | 78 | // Address of solution will be same as only adding rows - but be safe |
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| 79 | val = model.getColSolution(); |
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| 80 | printf("Solution %g %g\n",val[0],val[1]); |
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| 81 | #else |
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| 82 | { |
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| 83 | CbcModel model2(model); |
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| 84 | model2.branchAndBound(); |
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[1902] | 85 | //optimal = model2.isProvenOptimal(); // should be x0 = 2, x1 = 0.95 |
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[1140] | 86 | const double *val = model2.getColSolution(); |
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| 87 | printf("Solution %g %g\n",val[0],val[1]); |
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| 88 | } |
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| 89 | #endif |
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| 90 | return 0; |
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| 91 | } |
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