mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-05-08 00:05:46 +00:00
Code Activity

track the set of integer variables that are not set to integer values

Browse source 
Signed-off-by: Lev Nachmanson <levnach@microsoft.com>
This commit is contained in:
Lev Nachmanson 2017-07-21 21:09:51 -07:00
parent 64e542bd70
commit bd4fb22665
9 changed files with 66 additions and 32 deletions
Download patch file Download diff file Expand all files Collapse all files

38
src/util/lp/int_solver.cpp
View file

@ -21,7 +21,6 @@ void int_solver::fix_non_base_columns() {
return;
if (m_lar_solver->find_feasible_solution() == lp_status::INFEASIBLE)
failed();
init_inf_int_set();
lp_assert(is_feasible() && inf_int_set_is_correct());
}
@ -61,14 +60,22 @@ void int_solver::trace_inf_rows() const {
);
}
int_set& int_solver::inf_int_set() {
return m_lar_solver->m_inf_int_set;
}
const int_set& int_solver::inf_int_set() const {
return m_lar_solver->m_inf_int_set;
}
int int_solver::find_inf_int_base_column() {
if (m_inf_int_set.is_empty())
if (inf_int_set().is_empty())
return -1;
int j = find_inf_int_boxed_base_column_with_smallest_range();
if (j != -1)
return j;
unsigned k = settings().random_next() % m_inf_int_set.m_index.size();
return m_inf_int_set.m_index[k];
unsigned k = settings().random_next() % inf_int_set().m_index.size();
return inf_int_set().m_index[k];
}
int int_solver::find_inf_int_boxed_base_column_with_smallest_range() {
@ -79,7 +86,7 @@ int int_solver::find_inf_int_boxed_base_column_with_smallest_range() {
unsigned n = 0;
lar_core_solver & lcs = m_lar_solver->m_mpq_lar_core_solver;
for (int j : m_inf_int_set.m_index) {
for (int j : inf_int_set().m_index) {
lp_assert(is_base(j) && column_is_int_inf(j));
if (!is_boxed(j))
continue;
@ -331,7 +338,6 @@ lia_move int_solver::mk_gomory_cut(lar_term& t, mpq& k, explanation & expl) {
}
void int_solver::init_check_data() {
init_inf_int_set();
unsigned n = m_lar_solver->A_r().column_count();
m_old_values_set.resize(n);
m_old_values_data.resize(n);
@ -402,12 +408,13 @@ lia_move int_solver::check(lar_term& t, mpq& k, explanation& ex) {
if ((++m_branch_cut_counter) % settings().m_int_branch_cut_threshold == 0) {
move_non_base_vars_to_bounds();
move_non_base_vars_to_bounds(); // todo track changed variables
lp_status st = m_lar_solver->find_feasible_solution();
if (st != lp_status::FEASIBLE && st != lp_status::OPTIMAL) {
return lia_move::give_up;
}
init_inf_int_set(); // todo - can we avoid this call?
lp_assert(inf_int_set_is_correct());
// init_inf_int_set(); // todo - can we avoid this call?
int j = find_inf_int_base_column();
if (j != -1) {
// setup the call for gomory cut
@ -862,7 +869,7 @@ void int_solver::display_column(std::ostream & out, unsigned j) const {
bool int_solver::inf_int_set_is_correct() const {
for (unsigned j = 0; j < m_lar_solver->A_r().column_count(); j++) {
if (m_inf_int_set.contains(j) != (is_int(j) && (!value_is_int(j))))
if (inf_int_set().contains(j) != (is_int(j) && (!value_is_int(j))))
return false;
}
return true;
@ -872,20 +879,11 @@ bool int_solver::column_is_int_inf(unsigned j) const {
return is_int(j) && (!value_is_int(j));
}
void int_solver::init_inf_int_set() {
m_inf_int_set.clear();
m_inf_int_set.resize(m_lar_solver->A_r().column_count());
for (unsigned j = 0; j < m_lar_solver->A_r().column_count(); j++) {
if (column_is_int_inf(j))
m_inf_int_set.insert(j);
}
}
void int_solver::update_column_in_int_inf_set(unsigned j) {
if (is_int(j) && (!value_is_int(j)))
m_inf_int_set.insert(j);
inf_int_set().insert(j);
else
m_inf_int_set.erase(j);
inf_int_set().erase(j);
}
bool int_solver::is_base(unsigned j) const {