/*

 * Copyright 2008-2009 Katholieke Universiteit Leuven

 *

 * Use of this software is governed by the MIT license

 *

 * Written by Sven Verdoolaege, K.U.Leuven, Departement

 * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium

 */

#include <assert.h>

#include <isl/set.h>

#include <isl/vec.h>

#include <isl_ilp_private.h>

#include <isl_seq.h>

#include <isl_vec_private.h>

/* The input of this program is the same as that of the "polytope_minimize"

 * program from the barvinok distribution.

 *

 * Constraints of set is PolyLib format.

 * Linear or affine objective function in PolyLib format.

 */

static struct isl_vec *isl_vec_lin_to_aff(struct isl_vec *vec)

{

	struct isl_vec *aff;

	if (!vec)

		return NULL;

	aff = isl_vec_alloc(vec->ctx, 1 + vec->size);

	if (!aff)

		goto error;

	isl_int_set_si(aff->el[0], 0);

	isl_seq_cpy(aff->el + 1, vec->el, vec->size);

	isl_vec_free(vec);

	return aff;

error:

	isl_vec_free(vec);

	return NULL;

}

/* Rotate elements of vector right.

 * In particular, move the constant term from the end of the

 * vector to the start of the vector.

 */

static struct isl_vec *vec_ror(struct isl_vec *vec)

{

	int i;

	if (!vec)

		return NULL;

	for (i = vec->size - 2; i >= 0; --i)

		isl_int_swap(vec->el[i], vec->el[i + 1]);

	return vec;

}

int main(int argc, char **argv)

{

	struct isl_ctx *ctx = isl_ctx_alloc();

	struct isl_basic_set *bset;

	struct isl_vec *obj;

	struct isl_vec *sol;

	isl_int opt;

	unsigned dim;

	enum isl_lp_result res;

	isl_printer *p;

	isl_int_init(opt);

	bset = isl_basic_set_read_from_file(ctx, stdin);

	assert(bset);

	obj = isl_vec_read_from_file(ctx, stdin);

	assert(obj);

	dim = isl_basic_set_total_dim(bset);

	assert(obj->size >= dim && obj->size <= dim + 1);

	if (obj->size != dim + 1)

		obj = isl_vec_lin_to_aff(obj);

	else

		obj = vec_ror(obj);

	res = isl_basic_set_solve_ilp(bset, 0, obj->el, &opt, &sol);

	switch (res) {

	case isl_lp_error:

		fprintf(stderr, "error\n");

		return -1;

	case isl_lp_empty:

		fprintf(stdout, "empty\n");

		break;

	case isl_lp_unbounded:

		fprintf(stdout, "unbounded\n");

		break;

	case isl_lp_ok:

		p = isl_printer_to_file(ctx, stdout);

		p = isl_printer_print_vec(p, sol);

		p = isl_printer_end_line(p);

		p = isl_printer_print_isl_int(p, opt);

		p = isl_printer_end_line(p);

		isl_printer_free(p);

	}

	isl_basic_set_free(bset);

	isl_vec_free(obj);

	isl_vec_free(sol);

	isl_ctx_free(ctx);

	isl_int_clear(opt);

	return 0;

}