1 /*
2  * Copyright 2008-2009 Katholieke Universiteit Leuven
3  *
4  * Use of this software is governed by the MIT license
5  *
6  * Written by Sven Verdoolaege, K.U.Leuven, Departement
7  * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
8  */
9 
10 #include <assert.h>
11 #include <isl/set.h>
12 #include <isl/vec.h>
13 #include <isl_ilp_private.h>
14 #include <isl_seq.h>
15 #include <isl_vec_private.h>
16 
17 /* The input of this program is the same as that of the "polytope_minimize"
18  * program from the barvinok distribution.
19  *
20  * Constraints of set is PolyLib format.
21  * Linear or affine objective function in PolyLib format.
22  */
23 
isl_vec_lin_to_aff(struct isl_vec * vec)24 static struct isl_vec *isl_vec_lin_to_aff(struct isl_vec *vec)
25 {
26 	struct isl_vec *aff;
27 
28 	if (!vec)
29 		return NULL;
30 	aff = isl_vec_alloc(vec->ctx, 1 + vec->size);
31 	if (!aff)
32 		goto error;
33 	isl_int_set_si(aff->el[0], 0);
34 	isl_seq_cpy(aff->el + 1, vec->el, vec->size);
35 	isl_vec_free(vec);
36 	return aff;
37 error:
38 	isl_vec_free(vec);
39 	return NULL;
40 }
41 
42 /* Rotate elements of vector right.
43  * In particular, move the constant term from the end of the
44  * vector to the start of the vector.
45  */
vec_ror(struct isl_vec * vec)46 static struct isl_vec *vec_ror(struct isl_vec *vec)
47 {
48 	int i;
49 
50 	if (!vec)
51 		return NULL;
52 	for (i = vec->size - 2; i >= 0; --i)
53 		isl_int_swap(vec->el[i], vec->el[i + 1]);
54 	return vec;
55 }
56 
main(int argc,char ** argv)57 int main(int argc, char **argv)
58 {
59 	struct isl_ctx *ctx = isl_ctx_alloc();
60 	struct isl_basic_set *bset;
61 	struct isl_vec *obj;
62 	struct isl_vec *sol;
63 	isl_int opt;
64 	isl_size dim;
65 	enum isl_lp_result res;
66 	isl_printer *p;
67 
68 	isl_int_init(opt);
69 	bset = isl_basic_set_read_from_file(ctx, stdin);
70 	dim = isl_basic_set_dim(bset, isl_dim_all);
71 	assert(dim >= 0);
72 	obj = isl_vec_read_from_file(ctx, stdin);
73 	assert(obj);
74 	assert(obj->size >= dim && obj->size <= dim + 1);
75 	if (obj->size != dim + 1)
76 		obj = isl_vec_lin_to_aff(obj);
77 	else
78 		obj = vec_ror(obj);
79 	res = isl_basic_set_solve_ilp(bset, 0, obj->el, &opt, &sol);
80 	switch (res) {
81 	case isl_lp_error:
82 		fprintf(stderr, "error\n");
83 		return -1;
84 	case isl_lp_empty:
85 		fprintf(stdout, "empty\n");
86 		break;
87 	case isl_lp_unbounded:
88 		fprintf(stdout, "unbounded\n");
89 		break;
90 	case isl_lp_ok:
91 		p = isl_printer_to_file(ctx, stdout);
92 		p = isl_printer_print_vec(p, sol);
93 		p = isl_printer_end_line(p);
94 		p = isl_printer_print_isl_int(p, opt);
95 		p = isl_printer_end_line(p);
96 		isl_printer_free(p);
97 	}
98 	isl_basic_set_free(bset);
99 	isl_vec_free(obj);
100 	isl_vec_free(sol);
101 	isl_ctx_free(ctx);
102 	isl_int_clear(opt);
103 
104 	return 0;
105 }
106