/**
* Recursively count the number of leaves in a QUAST.
*
*/
static
int count_quast_leaves(PipQuast* q) {
if (!q)
return 0;
if (q->condition == NULL)
return 1;
else
return count_quast_leaves(q->next_else) + count_quast_leaves(q->next_then);
}
/**
* candl_ddv_constant_val: returns true iff all possible values of the
* minimization of the first variable of the system is a scalar constant
* (not parametric), and has the same value for all conditions of the QUAST.
* The scalar constant is put in the 'val' argument.
*
*/
static
int
candl_ddv_constant_val(CandlMatrix* system, int* val, int nb_par)
{
PipOptions * options;
PipQuast * solution;
int is_constant_val = 1;
int cst;
int cst_base = 42;
int first = 1;
int i, j;
// 1- Comute the lexmin of the system, to get a QUAST.
options = pip_options_init();
options->Simplify = 1;
options->Urs_parms = -1;
options->Urs_unknowns = -1;
options->Nq = 0;
CandlMatrix* context = candl_matrix_malloc(0, nb_par + 2);
solution = pip_solve(system, context, -1, options);
if ((solution != NULL) &&
((solution->list != NULL) || (solution->condition != NULL)))
{
// 2- Traverse all leaves, ensure they have the same value.
int nb_leaves = count_quast_leaves(solution);
PipList* leaveslist[nb_leaves + 1];
for (i = 0; i < nb_leaves + 1; ++i)
leaveslist[i] = NULL;
get_quast_leaves(solution, leaveslist);
for (i = 0; i < nb_leaves; ++i)
{
PipList* list = leaveslist[i];
if (list && list->vector)
{
PipVector* vect = list->vector;
for (j = 0; j < nb_par; ++j)
if (CANDL_get_si(vect->the_vector[j]) != 0)
{
is_constant_val = 0;
break;
}
if (is_constant_val)
{
cst = CANDL_get_si(vect->the_vector[vect->nb_elements - 1]);
if (first)
{
first = 0;
cst_base = cst;
}
else if (! first && cst != cst_base)
{
is_constant_val = 0;
break;
}
}
else
break;
}
}
}
pip_quast_free(solution);
pip_options_free(options);
candl_matrix_free(context);
if (is_constant_val)
*val = cst_base;
return is_constant_val;
}
