1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
|
import org.gnu.glpk.GLPK;
import org.gnu.glpk.GLPKConstants;
import org.gnu.glpk.GlpkException;
import org.gnu.glpk.glp_arc;
import org.gnu.glpk.glp_graph;
import org.gnu.glpk.glp_vertex;
import org.gnu.glpk.SWIGTYPE_p_double;
/**
* The program reads a minimum cost problem instance in DIMACS format from file,
* solves it by using the routine glp_mincost_relax4, and writes the solution
* found on the standard output.
*/
public class Relax4 {
public static void main(String[] arg) {
glp_graph g = null;
int ret;
int exitCode = 1;
String filename;
SWIGTYPE_p_double sol;
if (1 != arg.length) {
System.out.println("Usage: java Relax4 model.min");
System.exit(1);
}
GLPK.glp_java_set_numeric_locale("C");
filename = arg[0];
sol = GLPK.new_doubleArray(1);
try {
g = GLPK.glp_create_graph(
GLPKConstants.GLP_JAVA_V_SIZE,
GLPKConstants.GLP_JAVA_A_SIZE);
do {
GLPK.glp_java_set_numeric_locale("C");
ret = GLPK.glp_read_mincost(g,
GLPKConstants.GLP_JAVA_V_RHS,
GLPKConstants.GLP_JAVA_A_LOW,
GLPKConstants.GLP_JAVA_A_CAP,
GLPKConstants.GLP_JAVA_A_COST,
filename);
if (ret != 0) {
break;
}
ret = GLPK.glp_mincost_relax4(g,
GLPKConstants.GLP_JAVA_V_RHS,
GLPKConstants.GLP_JAVA_A_LOW,
GLPKConstants.GLP_JAVA_A_CAP,
GLPKConstants.GLP_JAVA_A_COST,
0,
sol,
GLPKConstants.GLP_JAVA_A_X,
GLPKConstants.GLP_JAVA_A_RC);
System.out.printf("ret = %d; sol = %5g\n", ret,
GLPK.doubleArray_getitem(sol, 0));
if (ret != 0) {
break;
}
for (int i = 1; i < g.getNv(); i++) {
glp_vertex v = GLPK.glp_java_vertex_get(g, i);
for (glp_arc a = v.getOut(); a != null;
a = a.getT_next()) {
glp_vertex w = a.getHead();
System.out.printf("arc %d->%d: x = %5g; rc = %5g\n",
v.getI(), w.getI(),
GLPK.glp_java_arc_get_data(a).getX(),
GLPK.glp_java_arc_get_data(a).getRc());
}
}
// signal success
exitCode = 0;
} while (false);
} catch (GlpkException e) {
// print error message
System.err.println(e.getMessage());
// signal failure
GLPK.delete_doubleArray(sol);
System.exit(1);
} finally {
if (g != null) {
GLPK.glp_delete_graph(g);
}
}
GLPK.delete_doubleArray(sol);
System.exit(exitCode);
}
}
|
