athos@1315: #include <iostream>
athos@1315: #include <lemon/lp_glpk.h>
athos@1315: using namespace lemon;
athos@1315: 
athos@1315: int main()
athos@1315: {     
athos@1318:  //The following example is taken from the documentation of the GLPK library.
athos@1318:  //See it in the GLPK reference manual and among the GLPK sample files (sample.c)
athos@1315:   LpGlpk lp;
athos@1315:   typedef LpGlpk::Row Row;
athos@1315:   typedef LpGlpk::Col Col;
athos@1318: 
athos@1318:   lp.max();
athos@1318: 
athos@1318:   Col x1 = lp.addCol();
athos@1318:   Col x2 = lp.addCol();
athos@1318:   Col x3 = lp.addCol();
athos@1318: 
athos@1318:   //One solution
athos@1318:   //   Row p = lp.addRow();
athos@1318:   //   Row q = lp.addRow();
athos@1318:   //   Row r = lp.addRow();
athos@1318:   //   lp.setRow(p,x1+x2+x3 <=100);  
athos@1318:   //   lp.setRow(q,10*x1+4*x2+5*x3<=600);  
athos@1318:   //   lp.setRow(r,2*x1+2*x2+6*x3<=300);  
athos@1318: 
athos@1318:   //A more elegant one
athos@1318:   //Constraints
athos@1318:   lp.addRow(x1+x2+x3 <=100);  
athos@1318:   lp.addRow(10*x1+4*x2+5*x3<=600);  
athos@1318:   lp.addRow(2*x1+2*x2+6*x3<=300);  
athos@1318:   //Nonnegativity of the variables
athos@1318:   lp.colLowerBound(x1, 0);
athos@1318:   lp.colLowerBound(x2, 0);
athos@1318:   lp.colLowerBound(x3, 0);
athos@1318:   //Objective function
athos@1318:   lp.setObj(10*x1+6*x2+4*x3);
athos@1318:   
athos@1318:   lp.solve();
athos@1338: 
athos@1338:   if (lp.primalStatus()==LpSolverBase::OPTIMAL){
athos@1338:     printf("Z = %g; x1 = %g; x2 = %g; x3 = %g\n", 
athos@1338: 	   lp.primalValue(), 
athos@1338: 	   lp.primal(x1), lp.primal(x2), lp.primal(x3));
athos@1338:   }
athos@1338:   else{
athos@1338:     std::cout<<"Optimal solution not found!"<<std::endl;
athos@1338:   }
athos@1338: 
athos@1318: 
athos@1318:   //Here comes the same problem written in C using GLPK API routines
athos@1315: 
athos@1315: //   LPX *lp;
athos@1315: //       int ia[1+1000], ja[1+1000];
athos@1315: //       double ar[1+1000], Z, x1, x2, x3;
athos@1315: // s1:   lp = lpx_create_prob();
athos@1315: // s2:   lpx_set_prob_name(lp, "sample");
athos@1315: // s3:   lpx_set_obj_dir(lp, LPX_MAX);
athos@1315: // s4:   lpx_add_rows(lp, 3);
athos@1315: // s5:   lpx_set_row_name(lp, 1, "p");
athos@1315: // s6:   lpx_set_row_bnds(lp, 1, LPX_UP, 0.0, 100.0);
athos@1315: // s7:   lpx_set_row_name(lp, 2, "q");
athos@1315: // s8:   lpx_set_row_bnds(lp, 2, LPX_UP, 0.0, 600.0);
athos@1315: // s9:   lpx_set_row_name(lp, 3, "r");
athos@1315: // s10:  lpx_set_row_bnds(lp, 3, LPX_UP, 0.0, 300.0);
athos@1315: // s11:  lpx_add_cols(lp, 3);
athos@1315: // s12:  lpx_set_col_name(lp, 1, "x1");
athos@1315: // s13:  lpx_set_col_bnds(lp, 1, LPX_LO, 0.0, 0.0);
athos@1315: // s14:  lpx_set_obj_coef(lp, 1, 10.0);
athos@1315: // s15:  lpx_set_col_name(lp, 2, "x2");
athos@1315: // s16:  lpx_set_col_bnds(lp, 2, LPX_LO, 0.0, 0.0);
athos@1315: // s17:  lpx_set_obj_coef(lp, 2, 6.0);
athos@1315: // s18:  lpx_set_col_name(lp, 3, "x3");
athos@1315: // s19:  lpx_set_col_bnds(lp, 3, LPX_LO, 0.0, 0.0);
athos@1315: // s20:  lpx_set_obj_coef(lp, 3, 4.0);
athos@1315: // s21:  ia[1] = 1, ja[1] = 1, ar[1] =  1.0; /* a[1,1] =  1 */
athos@1315: // s22:  ia[2] = 1, ja[2] = 2, ar[2] =  1.0; /* a[1,2] =  1 */
athos@1315: // s23:  ia[3] = 1, ja[3] = 3, ar[3] =  1.0; /* a[1,3] =  1 */
athos@1315: // s24:  ia[4] = 2, ja[4] = 1, ar[4] = 10.0; /* a[2,1] = 10 */
athos@1315: // s25:  ia[5] = 3, ja[5] = 1, ar[5] =  2.0; /* a[3,1] =  2 */
athos@1315: // s26:  ia[6] = 2, ja[6] = 2, ar[6] =  4.0; /* a[2,2] =  4 */
athos@1315: // s27:  ia[7] = 3, ja[7] = 2, ar[7] =  2.0; /* a[3,2] =  2 */
athos@1315: // s28:  ia[8] = 2, ja[8] = 3, ar[8] =  5.0; /* a[2,3] =  5 */
athos@1315: // s29:  ia[9] = 3, ja[9] = 3, ar[9] =  6.0; /* a[3,3] =  6 */
athos@1315: // s30:  lpx_load_matrix(lp, 9, ia, ja, ar);
athos@1315: // s31:  lpx_simplex(lp);
athos@1315: // s32:  Z = lpx_get_obj_val(lp);
athos@1315: // s33:  x1 = lpx_get_col_prim(lp, 1);
athos@1315: // s34:  x2 = lpx_get_col_prim(lp, 2);
athos@1315: // s35:  x3 = lpx_get_col_prim(lp, 3);
athos@1315: // s36:  printf("\nZ = %g; x1 = %g; x2 = %g; x3 = %g\n", Z, x1, x2, x3);
athos@1315: // s37:  lpx_delete_prob(lp);
athos@1315: //       return 0;
athos@1318: 
athos@1315:   return 0;
athos@1315: }