9 #include <lemon/lp_glpk.h>
11 #include <lemon/lp_cplex.h>
14 using namespace lemon;
17 typedef LpGlpk LpDefault;
19 typedef LpCplex LpDefault;
24 //The following example is taken from the documentation of the GLPK library.
25 //See it in the GLPK reference manual and among the GLPK sample files (sample.c)
27 //A default solver is taken
29 typedef LpDefault::Row Row;
30 typedef LpDefault::Col Col;
33 //This will be a maximization
36 //We add coloumns (variables) to our problem
42 lp.addRow(x1+x2+x3 <=100);
43 lp.addRow(10*x1+4*x2+5*x3<=600);
44 lp.addRow(2*x1+2*x2+6*x3<=300);
45 //Nonnegativity of the variables
46 lp.colLowerBound(x1, 0);
47 lp.colLowerBound(x2, 0);
48 lp.colLowerBound(x3, 0);
50 lp.setObj(10*x1+6*x2+4*x3);
52 //Call the routine of the underlying LP solver
56 if (lp.primalStatus()==LpSolverBase::OPTIMAL){
57 printf("Z = %g; x1 = %g; x2 = %g; x3 = %g\n",
59 lp.primal(x1), lp.primal(x2), lp.primal(x3));
62 std::cout<<"Optimal solution not found!"<<std::endl;
65 //End of LEMON style code
67 //Here comes the same problem written in C using GLPK API routines
70 // int ia[1+1000], ja[1+1000];
71 // double ar[1+1000], Z, x1, x2, x3;
72 // s1: lp = lpx_create_prob();
73 // s2: lpx_set_prob_name(lp, "sample");
74 // s3: lpx_set_obj_dir(lp, LPX_MAX);
75 // s4: lpx_add_rows(lp, 3);
76 // s5: lpx_set_row_name(lp, 1, "p");
77 // s6: lpx_set_row_bnds(lp, 1, LPX_UP, 0.0, 100.0);
78 // s7: lpx_set_row_name(lp, 2, "q");
79 // s8: lpx_set_row_bnds(lp, 2, LPX_UP, 0.0, 600.0);
80 // s9: lpx_set_row_name(lp, 3, "r");
81 // s10: lpx_set_row_bnds(lp, 3, LPX_UP, 0.0, 300.0);
82 // s11: lpx_add_cols(lp, 3);
83 // s12: lpx_set_col_name(lp, 1, "x1");
84 // s13: lpx_set_col_bnds(lp, 1, LPX_LO, 0.0, 0.0);
85 // s14: lpx_set_obj_coef(lp, 1, 10.0);
86 // s15: lpx_set_col_name(lp, 2, "x2");
87 // s16: lpx_set_col_bnds(lp, 2, LPX_LO, 0.0, 0.0);
88 // s17: lpx_set_obj_coef(lp, 2, 6.0);
89 // s18: lpx_set_col_name(lp, 3, "x3");
90 // s19: lpx_set_col_bnds(lp, 3, LPX_LO, 0.0, 0.0);
91 // s20: lpx_set_obj_coef(lp, 3, 4.0);
92 // s21: ia[1] = 1, ja[1] = 1, ar[1] = 1.0; /* a[1,1] = 1 */
93 // s22: ia[2] = 1, ja[2] = 2, ar[2] = 1.0; /* a[1,2] = 1 */
94 // s23: ia[3] = 1, ja[3] = 3, ar[3] = 1.0; /* a[1,3] = 1 */
95 // s24: ia[4] = 2, ja[4] = 1, ar[4] = 10.0; /* a[2,1] = 10 */
96 // s25: ia[5] = 3, ja[5] = 1, ar[5] = 2.0; /* a[3,1] = 2 */
97 // s26: ia[6] = 2, ja[6] = 2, ar[6] = 4.0; /* a[2,2] = 4 */
98 // s27: ia[7] = 3, ja[7] = 2, ar[7] = 2.0; /* a[3,2] = 2 */
99 // s28: ia[8] = 2, ja[8] = 3, ar[8] = 5.0; /* a[2,3] = 5 */
100 // s29: ia[9] = 3, ja[9] = 3, ar[9] = 6.0; /* a[3,3] = 6 */
101 // s30: lpx_load_matrix(lp, 9, ia, ja, ar);
102 // s31: lpx_simplex(lp);
103 // s32: Z = lpx_get_obj_val(lp);
104 // s33: x1 = lpx_get_col_prim(lp, 1);
105 // s34: x2 = lpx_get_col_prim(lp, 2);
106 // s35: x3 = lpx_get_col_prim(lp, 3);
107 // s36: printf("\nZ = %g; x1 = %g; x2 = %g; x3 = %g\n", Z, x1, x2, x3);
108 // s37: lpx_delete_prob(lp);