demo/mip_demo.cc
author alpar
Fri, 08 Feb 2008 11:04:37 +0000
changeset 2571 f5c6e63f51d1
parent 2492 387f6ff851ef
permissions -rw-r--r--
Hopefully fix all compilation errors.
     1 /* -*- C++ -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library
     4  *
     5  * Copyright (C) 2003-2008
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     8  *
     9  * Permission to use, modify and distribute this software is granted
    10  * provided that this copyright notice appears in all copies. For
    11  * precise terms see the accompanying LICENSE file.
    12  *
    13  * This software is provided "AS IS" with no warranty of any kind,
    14  * express or implied, and with no claim as to its suitability for any
    15  * purpose.
    16  *
    17  */
    18 
    19 ///\ingroup demos
    20 ///\file
    21 ///\brief Mixed integer program solver demo
    22 ///
    23 /// This example shows how can we solve an integer program with lemon
    24 /// \c Mip interface and with default solver.
    25 ///
    26 /// \include mip_demo.cc
    27 
    28 #include <lemon/lp.h>
    29 
    30 using namespace lemon;
    31 
    32 int main(){
    33 
    34    Mip ilp;
    35 
    36 
    37   typedef Mip::Row Row;
    38   typedef Mip::Col Col;
    39   
    40   ilp.max();
    41   
    42   Col x1 = ilp.addCol();
    43   Col x2 = ilp.addCol();
    44   Col x3 = ilp.addCol();
    45   
    46   ilp.integer(x1,true);
    47   ilp.integer(x2,true);
    48   ilp.integer(x3,true);
    49   
    50   ilp.addRow(x1+x2+x3 <=100);  
    51   ilp.addRow(10*x1+4*x2+5*x3<=600);  
    52   ilp.addRow(2*x1+2*x2+6*x3<=300); 
    53   
    54   ilp.colLowerBound(x1, 0);
    55   ilp.colLowerBound(x2, 0);
    56   ilp.colLowerBound(x3, 0);
    57   //Objective function
    58   ilp.obj(10*x1+6*x2+4*x3);
    59   
    60   //Call the routine of the underlying LP solver
    61   ilp.solve();
    62   
    63   //Print results
    64   if (ilp.primalStatus()==LpSolverBase::OPTIMAL){
    65     std::cout<<"Optimal solution found!"<<std::endl;
    66     printf("optimum value = %g; x1 = %g; x2 = %g; x3 = %g\n", 
    67            ilp.primalValue(), 
    68            ilp.primal(x1), ilp.primal(x2), ilp.primal(x3));
    69   }
    70   else{
    71     std::cout<<"Optimal solution not found!"<<std::endl;
    72   }
    73 
    74 }