athos@2144: /* -*- C++ -*-
athos@2144:  *
athos@2144:  * This file is a part of LEMON, a generic C++ optimization library
athos@2144:  *
alpar@2553:  * Copyright (C) 2003-2008
athos@2144:  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
athos@2144:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
athos@2144:  *
athos@2144:  * Permission to use, modify and distribute this software is granted
athos@2144:  * provided that this copyright notice appears in all copies. For
athos@2144:  * precise terms see the accompanying LICENSE file.
athos@2144:  *
athos@2144:  * This software is provided "AS IS" with no warranty of any kind,
athos@2144:  * express or implied, and with no claim as to its suitability for any
athos@2144:  * purpose.
athos@2144:  *
athos@2144:  */
athos@2144: 
athos@2144: ///\file
athos@2218: ///\brief Implementation of the LEMON-GLPK mip solver interface.
athos@2144: 
athos@2144: #include <lemon/mip_glpk.h>
athos@2144: 
deba@2441: #if GLP_MAJOR_VERSION > 4 || (GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION > 15)
deba@2441: #define LEMON_glp(func) (glp_##func)
deba@2441: #define LEMON_lpx(func) (lpx_##func)
deba@2441: 
deba@2441: #define LEMON_GLP(def) (GLP_##def)
deba@2441: #define LEMON_LPX(def) (LPX_##def)
deba@2441: 
deba@2441: #else
deba@2441: 
deba@2441: #define LEMON_glp(func) (lpx_##func)
deba@2441: #define LEMON_lpx(func) (lpx_##func)
deba@2441: 
deba@2441: #define LEMON_GLP(def) (LPX_##def)
deba@2441: #define LEMON_LPX(def) (LPX_##def)
deba@2441: 
deba@2441: #endif
deba@2441: 
athos@2144: namespace lemon {
athos@2144:   
athos@2144:   MipGlpk::MipGlpk() {
deba@2441: #if !(GLP_MAJOR_VERSION > 4 || (GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION > 15))
deba@2441:     LEMON_lpx(set_class)(lp,LEMON_GLP(MIP));
deba@2441: #endif
athos@2144:   }
athos@2148: 
athos@2149:   void MipGlpk::_colType(int i, MipGlpk::ColTypes col_type){
athos@2148:     switch (col_type){
athos@2267:       case INT:
deba@2441: 	LEMON_glp(set_col_kind)(lp,i,LEMON_GLP(IV));
athos@2148: 	break;
athos@2148:       case REAL:
deba@2441: 	LEMON_glp(set_col_kind)(lp,i,LEMON_GLP(CV));
athos@2148: 	break;
athos@2149:     default:;
athos@2148:         //FIXME problem
athos@2144:     }
athos@2144:   }
athos@2144:   
deba@2366:   MipGlpk::ColTypes MipGlpk::_colType(int i) const {
deba@2441:     switch (LEMON_glp(get_col_kind)(lp,i)){
deba@2441:     case LEMON_GLP(IV):
athos@2267:       return INT;//Or binary
deba@2441:     case LEMON_GLP(CV):
athos@2148:       return REAL;
athos@2148:     default:
athos@2148:       return REAL;//Error!
athos@2144:     }
athos@2148:     
athos@2144:   }
athos@2144:   
deba@2366:   LpGlpk::SolveExitStatus MipGlpk::_solve() {
deba@2441:     int result = LEMON_lpx(simplex)(lp);
deba@2441: 
deba@2441:     // hack: mip does not contain integer variable 
deba@2458: #if GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION == 16
deba@2441:     int tmp = -1;
deba@2441:     if (LEMON_glp(get_num_int(lp)) == 0) {
deba@2441:       tmp = LEMON_lpx(add_cols)(lp, 1);
deba@2441:       LEMON_glp(set_col_bnds)(lp, tmp, LEMON_GLP(FX), 0.0, 0.0);
deba@2441:       LEMON_glp(set_col_kind)(lp, tmp, LEMON_GLP(IV));
deba@2441:     }
deba@2441: #endif
deba@2441: 
deba@2441:     if (LEMON_lpx(get_status)(lp)==LEMON_LPX(OPT)) {
athos@2213:       //Maybe we could try the routine lpx_intopt(lp), a revised
athos@2213:       //version of lpx_integer
deba@2441: 
deba@2441:       result = LEMON_lpx(integer)(lp);
athos@2213:       switch (result){
deba@2441:       case LEMON_LPX(E_OK):
deba@2441: 	solved = true;
deba@2442: 	break;
athos@2144:       default:
deba@2441: 	solved = false;
deba@2441:       }  
deba@2441:     } else {
deba@2441:       solved = false;
athos@2144:     }
deba@2458: #if GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION == 16
deba@2441:     if (tmp != -1) {
deba@2441:       int tmpa[2];
deba@2441:       tmpa[1] = tmp;
deba@2441:       LEMON_lpx(del_cols)(lp, 1, tmpa);
deba@2441:     }
deba@2441: #endif
deba@2441:     return solved ? SOLVED : UNSOLVED;
athos@2144:   }
athos@2185: 
athos@2185: 
deba@2366:   LpGlpk::SolutionStatus MipGlpk::_getMipStatus() const {
athos@2185: 
deba@2441:     if (LEMON_lpx(get_status)(lp)==LEMON_LPX(OPT)){
athos@2213:       //Meg kell nezni: ha az LP is infinite, akkor ez is, ha az is
athos@2213:       //infeasible, akkor ez is, de ez lehet maskepp is infeasible.
deba@2441:       int stat= LEMON_lpx(mip_status)(lp);
athos@2213:       
athos@2213:       switch (stat) {
deba@2441:       case LEMON_LPX(I_UNDEF)://Undefined (no solve has been run yet)
athos@2213: 	return UNDEFINED;
deba@2441:       case LEMON_LPX(I_NOFEAS)://There is no feasible integral solution
athos@2213: 	return INFEASIBLE;
deba@2441: 	//     case LEMON_LPX(UNBND)://Unbounded
athos@2213: 	//       return INFINITE;
deba@2441:       case LEMON_LPX(I_FEAS)://Feasible
athos@2213: 	return FEASIBLE;
deba@2441:       case LEMON_LPX(I_OPT)://Feasible
athos@2213: 	return OPTIMAL;
athos@2213:       default:
deba@2441: 	return UNDEFINED; //to avoid gcc warning
athos@2185:       //FIXME error
athos@2213:       }
athos@2185:     }
athos@2213:     else 
athos@2213:       return UNDEFINED; //Maybe we could refine this: what does the LP
athos@2213: 			//relaxation look like
athos@2213:       
athos@2185:   }  
athos@2185: 
deba@2366:   MipGlpk::Value MipGlpk::_getPrimal(int i) const {
deba@2441:     return LEMON_glp(mip_col_val)(lp,i);
athos@2144:   }
athos@2144:   
deba@2366:   MipGlpk::Value MipGlpk::_getPrimalValue() const {
deba@2441:     return LEMON_glp(mip_obj_val)(lp);
athos@2144:   }
athos@2218: } //END OF NAMESPACE LEMON