static Boolean same_homology(
Triangulation *manifold0,
Triangulation *manifold1)
{
AbelianGroup *g0,
*g1;
Boolean groups_are_isomorphic;
int i;
/*
* Compute the homology groups.
*/
g0 = homology(manifold0);
g1 = homology(manifold1);
/*
* compute_isometries() has already checked that both manifolds
* really are manifolds, so neither g0 nor g1 should be NULL.
*/
if (g0 == NULL || g1 == NULL)
uFatalError("same_homology", "isometry");
/*
* Put the homology groups into a canonical form.
*/
compress_abelian_group(g0);
compress_abelian_group(g1);
/*
* Compare the groups.
*/
if (g0->num_torsion_coefficients != g1->num_torsion_coefficients)
groups_are_isomorphic = FALSE;
else
{
groups_are_isomorphic = TRUE; /* innocent until proven guilty */
for (i = 0; i < g0->num_torsion_coefficients; i++)
if (g0->torsion_coefficients[i] != g1->torsion_coefficients[i])
groups_are_isomorphic = FALSE;
}
/*
* Free the Abelian groups.
*/
free_abelian_group(g0);
free_abelian_group(g1);
return groups_are_isomorphic;
}
void free_symmetry_group(
SymmetryGroup *symmetry_group)
{
if (symmetry_group != NULL)
{
int i;
free_isometry_list(symmetry_group->symmetry_list);
for (i = 0; i < symmetry_group->order; i++)
my_free(symmetry_group->product[i]);
my_free(symmetry_group->product);
my_free(symmetry_group->order_of_element);
my_free(symmetry_group->inverse);
if (symmetry_group->abelian_description != NULL)
free_abelian_group(symmetry_group->abelian_description);
if (symmetry_group->is_direct_product == TRUE)
for (i = 0; i < 2; i++)
free_symmetry_group(symmetry_group->factor[i]);
my_free(symmetry_group);
}
}
