deba@458: /* -*- mode: C++; indent-tabs-mode: nil; -*-
deba@458:  *
deba@458:  * This file is a part of LEMON, a generic C++ optimization library.
deba@458:  *
deba@458:  * Copyright (C) 2003-2008
deba@458:  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
deba@458:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
deba@458:  *
deba@458:  * Permission to use, modify and distribute this software is granted
deba@458:  * provided that this copyright notice appears in all copies. For
deba@458:  * precise terms see the accompanying LICENSE file.
deba@458:  *
deba@458:  * This software is provided "AS IS" with no warranty of any kind,
deba@458:  * express or implied, and with no claim as to its suitability for any
deba@458:  * purpose.
deba@458:  *
deba@458:  */
deba@458: 
deba@458: ///\file
deba@458: ///\brief Implementation of the LEMON-GLPK mip solver interface.
deba@458: 
deba@458: #include <lemon/mip_glpk.h>
deba@458: 
deba@458: extern "C" {
deba@458: #include <glpk.h>
deba@458: }
deba@458: 
deba@458: #if GLP_MAJOR_VERSION > 4 || (GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION > 15)
deba@458: #define LEMON_glp(func) (glp_##func)
deba@458: #define LEMON_lpx(func) (lpx_##func)
deba@458: 
deba@458: #define LEMON_GLP(def) (GLP_##def)
deba@458: #define LEMON_LPX(def) (LPX_##def)
deba@458: 
deba@458: #else
deba@458: 
deba@458: #define LEMON_glp(func) (lpx_##func)
deba@458: #define LEMON_lpx(func) (lpx_##func)
deba@458: 
deba@458: #define LEMON_GLP(def) (LPX_##def)
deba@458: #define LEMON_LPX(def) (LPX_##def)
deba@458: 
deba@458: #endif
deba@458: 
deba@458: namespace lemon {
deba@458: 
deba@458:   MipGlpk::MipGlpk() {
deba@458: #if !(GLP_MAJOR_VERSION > 4 || \
deba@458:       (GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION > 15))
deba@458:     LEMON_lpx(set_class)(lp,LEMON_GLP(MIP));
deba@458: #endif
deba@458:   }
deba@458: 
deba@458:   void MipGlpk::_colType(int i, MipGlpk::ColTypes col_type){
deba@458:     switch (col_type){
deba@458:       case INT:
deba@458:         LEMON_glp(set_col_kind)(lp,i,LEMON_GLP(IV));
deba@458:         break;
deba@458:       case REAL:
deba@458:         LEMON_glp(set_col_kind)(lp,i,LEMON_GLP(CV));
deba@458:         break;
deba@458:     default:;
deba@458:         //FIXME problem
deba@458:     }
deba@458:   }
deba@458: 
deba@458:   MipGlpk::ColTypes MipGlpk::_colType(int i) const {
deba@458:     switch (LEMON_glp(get_col_kind)(lp,i)){
deba@458:     case LEMON_GLP(IV):
deba@458:       return INT;//Or binary
deba@458:     case LEMON_GLP(CV):
deba@458:       return REAL;
deba@458:     default:
deba@458:       return REAL;//Error!
deba@458:     }
deba@458: 
deba@458:   }
deba@458: 
deba@458:   LpGlpk::SolveExitStatus MipGlpk::_solve() {
deba@458:     int result = LEMON_lpx(simplex)(lp);
deba@458: 
deba@458:     // hack: mip does not contain integer variable
deba@458: #if GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION == 16
deba@458:     int tmp = -1;
deba@458:     if (LEMON_glp(get_num_int(lp)) == 0) {
deba@458:       tmp = LEMON_lpx(add_cols)(lp, 1);
deba@458:       LEMON_glp(set_col_bnds)(lp, tmp, LEMON_GLP(FX), 0.0, 0.0);
deba@458:       LEMON_glp(set_col_kind)(lp, tmp, LEMON_GLP(IV));
deba@458:     }
deba@458: #endif
deba@458: 
deba@458:     if (LEMON_lpx(get_status)(lp)==LEMON_LPX(OPT)) {
deba@458:       //Maybe we could try the routine lpx_intopt(lp), a revised
deba@458:       //version of lpx_integer
deba@458: 
deba@458:       result = LEMON_lpx(integer)(lp);
deba@458:       switch (result){
deba@458:       case LEMON_LPX(E_OK):
deba@458:         solved = true;
deba@458:         break;
deba@458:       default:
deba@458:         solved = false;
deba@458:       }
deba@458:     } else {
deba@458:       solved = false;
deba@458:     }
deba@458: #if GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION == 16
deba@458:     if (tmp != -1) {
deba@458:       int tmpa[2];
deba@458:       tmpa[1] = tmp;
deba@458:       LEMON_lpx(del_cols)(lp, 1, tmpa);
deba@458:     }
deba@458: #endif
deba@458:     return solved ? SOLVED : UNSOLVED;
deba@458:   }
deba@458: 
deba@458: 
deba@458:   LpGlpk::SolutionStatus MipGlpk::_getMipStatus() const {
deba@458: 
deba@458:     if (LEMON_lpx(get_status)(lp)==LEMON_LPX(OPT)){
deba@458:       //Meg kell nezni: ha az LP is infinite, akkor ez is, ha az is
deba@458:       //infeasible, akkor ez is, de ez lehet maskepp is infeasible.
deba@458:       int stat= LEMON_lpx(mip_status)(lp);
deba@458: 
deba@458:       switch (stat) {
deba@458:       case LEMON_LPX(I_UNDEF)://Undefined (no solve has been run yet)
deba@458:         return UNDEFINED;
deba@458:       case LEMON_LPX(I_NOFEAS)://There is no feasible integral solution
deba@458:         return INFEASIBLE;
deba@458:         //     case LEMON_LPX(UNBND)://Unbounded
deba@458:         //       return INFINITE;
deba@458:       case LEMON_LPX(I_FEAS)://Feasible
deba@458:         return FEASIBLE;
deba@458:       case LEMON_LPX(I_OPT)://Feasible
deba@458:         return OPTIMAL;
deba@458:       default:
deba@458:         return UNDEFINED; //to avoid gcc warning
deba@458:       //FIXME error
deba@458:       }
deba@458:     }
deba@458:     else
deba@458:       return UNDEFINED; //Maybe we could refine this: what does the LP
deba@458:                         //relaxation look like
deba@458: 
deba@458:   }
deba@458: 
deba@458:   MipGlpk::Value MipGlpk::_getPrimal(int i) const {
deba@458:     return LEMON_glp(mip_col_val)(lp,i);
deba@458:   }
deba@458: 
deba@458:   MipGlpk::Value MipGlpk::_getPrimalValue() const {
deba@458:     return LEMON_glp(mip_obj_val)(lp);
deba@458:   }
deba@458: } //END OF NAMESPACE LEMON