Module: ppl/ppl Branch: master Commit: 09144610d98413a390afed2c0f5b189e7a9e5f30 URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=09144610d9841...

Author: Enea Zaffanella zaffanella@cs.unipr.it Date: Mon Oct 17 09:52:30 2011 +0200

Fixed MIP_Problem bug shown by tests/MIP_Problem/mipproblem4.cc.

---

src/MIP_Problem.cc | 11 ++++++++++- 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/src/MIP_Problem.cc b/src/MIP_Problem.cc index ed19471..9224ceb 100644 --- a/src/MIP_Problem.cc +++ b/src/MIP_Problem.cc @@ -1701,6 +1701,13 @@ PPL::MIP_Problem::erase_artificials(const dimension_type begin_artificials, // See page 55 of [PapadimitriouS98]. void PPL::MIP_Problem::compute_generator() const { + // Early exit for 0-dimensional problems. + if (external_space_dim == 0) { + MIP_Problem& x = const_cast<MIP_Problem&>(*this); + x.last_generator = point(); + return; + } + // We will store in num[] and in den[] the numerators and // the denominators of every variable of the original problem. std::vector<Coefficient> num(external_space_dim); @@ -1772,6 +1779,7 @@ PPL::MIP_Problem::compute_generator() const { }

// Compute the lcm of all denominators. + PPL_ASSERT(external_space_dim > 0); lcm = den[0]; for (dimension_type i = 1; i < external_space_dim; ++i) lcm_assign(lcm, lcm, den[i]); @@ -1794,7 +1802,8 @@ PPL::MIP_Problem::compute_generator() const { void PPL::MIP_Problem::second_phase() { // Second_phase requires that *this is satisfiable. - PPL_ASSERT(status == SATISFIABLE || status == UNBOUNDED + PPL_ASSERT(status == SATISFIABLE + || status == UNBOUNDED || status == OPTIMIZED); // In the following cases the problem is already solved. if (status == UNBOUNDED || status == OPTIMIZED)