2 #include <lemon/lp_glpk.h>
7 //The following example is taken from the documentation of the GLPK library.
8 //See it in the GLPK reference manual and among the GLPK sample files (sample.c)
10 typedef LpGlpk::Row Row;
11 typedef LpGlpk::Col Col;
20 // Row p = lp.addRow();
21 // Row q = lp.addRow();
22 // Row r = lp.addRow();
23 // lp.setRow(p,x1+x2+x3 <=100);
24 // lp.setRow(q,10*x1+4*x2+5*x3<=600);
25 // lp.setRow(r,2*x1+2*x2+6*x3<=300);
29 lp.addRow(x1+x2+x3 <=100);
30 lp.addRow(10*x1+4*x2+5*x3<=600);
31 lp.addRow(2*x1+2*x2+6*x3<=300);
32 //Nonnegativity of the variables
33 lp.colLowerBound(x1, 0);
34 lp.colLowerBound(x2, 0);
35 lp.colLowerBound(x3, 0);
37 lp.setObj(10*x1+6*x2+4*x3);
41 if (lp.primalStatus()==LpSolverBase::OPTIMAL){
42 printf("Z = %g; x1 = %g; x2 = %g; x3 = %g\n",
44 lp.primal(x1), lp.primal(x2), lp.primal(x3));
47 std::cout<<"Optimal solution not found!"<<std::endl;
51 //Here comes the same problem written in C using GLPK API routines
54 // int ia[1+1000], ja[1+1000];
55 // double ar[1+1000], Z, x1, x2, x3;
56 // s1: lp = lpx_create_prob();
57 // s2: lpx_set_prob_name(lp, "sample");
58 // s3: lpx_set_obj_dir(lp, LPX_MAX);
59 // s4: lpx_add_rows(lp, 3);
60 // s5: lpx_set_row_name(lp, 1, "p");
61 // s6: lpx_set_row_bnds(lp, 1, LPX_UP, 0.0, 100.0);
62 // s7: lpx_set_row_name(lp, 2, "q");
63 // s8: lpx_set_row_bnds(lp, 2, LPX_UP, 0.0, 600.0);
64 // s9: lpx_set_row_name(lp, 3, "r");
65 // s10: lpx_set_row_bnds(lp, 3, LPX_UP, 0.0, 300.0);
66 // s11: lpx_add_cols(lp, 3);
67 // s12: lpx_set_col_name(lp, 1, "x1");
68 // s13: lpx_set_col_bnds(lp, 1, LPX_LO, 0.0, 0.0);
69 // s14: lpx_set_obj_coef(lp, 1, 10.0);
70 // s15: lpx_set_col_name(lp, 2, "x2");
71 // s16: lpx_set_col_bnds(lp, 2, LPX_LO, 0.0, 0.0);
72 // s17: lpx_set_obj_coef(lp, 2, 6.0);
73 // s18: lpx_set_col_name(lp, 3, "x3");
74 // s19: lpx_set_col_bnds(lp, 3, LPX_LO, 0.0, 0.0);
75 // s20: lpx_set_obj_coef(lp, 3, 4.0);
76 // s21: ia[1] = 1, ja[1] = 1, ar[1] = 1.0; /* a[1,1] = 1 */
77 // s22: ia[2] = 1, ja[2] = 2, ar[2] = 1.0; /* a[1,2] = 1 */
78 // s23: ia[3] = 1, ja[3] = 3, ar[3] = 1.0; /* a[1,3] = 1 */
79 // s24: ia[4] = 2, ja[4] = 1, ar[4] = 10.0; /* a[2,1] = 10 */
80 // s25: ia[5] = 3, ja[5] = 1, ar[5] = 2.0; /* a[3,1] = 2 */
81 // s26: ia[6] = 2, ja[6] = 2, ar[6] = 4.0; /* a[2,2] = 4 */
82 // s27: ia[7] = 3, ja[7] = 2, ar[7] = 2.0; /* a[3,2] = 2 */
83 // s28: ia[8] = 2, ja[8] = 3, ar[8] = 5.0; /* a[2,3] = 5 */
84 // s29: ia[9] = 3, ja[9] = 3, ar[9] = 6.0; /* a[3,3] = 6 */
85 // s30: lpx_load_matrix(lp, 9, ia, ja, ar);
86 // s31: lpx_simplex(lp);
87 // s32: Z = lpx_get_obj_val(lp);
88 // s33: x1 = lpx_get_col_prim(lp, 1);
89 // s34: x2 = lpx_get_col_prim(lp, 2);
90 // s35: x3 = lpx_get_col_prim(lp, 3);
91 // s36: printf("\nZ = %g; x1 = %g; x2 = %g; x3 = %g\n", Z, x1, x2, x3);
92 // s37: lpx_delete_prob(lp);