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z3/src/util/lp/bound_propagator.cpp
Lev 22213a9e73 rebase
Signed-off-by: Lev <levnach@hotmail.com>
2018-09-14 11:53:54 -07:00

59 lines
2.7 KiB
C++

/*
Copyright (c) 2017 Microsoft Corporation
Author: Lev Nachmanson
*/
#include "util/lp/lar_solver.h"
namespace lp {
bound_propagator::bound_propagator(lar_solver & ls):
m_lar_solver(ls) {}
column_type bound_propagator::get_column_type(unsigned j) const {
return m_lar_solver.m_mpq_lar_core_solver.m_column_types()[j];
}
const impq & bound_propagator::get_lower_bound(unsigned j) const {
return m_lar_solver.m_mpq_lar_core_solver.m_r_lower_bounds()[j];
}
const impq & bound_propagator::get_upper_bound(unsigned j) const {
return m_lar_solver.m_mpq_lar_core_solver.m_r_upper_bounds()[j];
}
void bound_propagator::try_add_bound(mpq v, unsigned j, bool is_low, bool coeff_before_j_is_pos, unsigned row_or_term_index, bool strict) {
j = m_lar_solver.adjust_column_index_to_term_index(j);
if (m_lar_solver.is_term(j)) {
// lp treats terms as not having a free coefficient, restoring it below for the outside consumption
v += m_lar_solver.get_term(j).m_v;
}
lconstraint_kind kind = is_low? GE : LE;
if (strict)
kind = static_cast<lconstraint_kind>(kind / 2);
if (!bound_is_interesting(j, kind, v))
return;
unsigned k; // index to ibounds
if (is_low) {
if (try_get_value(m_improved_lower_bounds, j, k)) {
auto & found_bound = m_ibounds[k];
if (v > found_bound.m_bound || (v == found_bound.m_bound && found_bound.m_strict == false && strict)) {
found_bound = implied_bound(v, j, is_low, coeff_before_j_is_pos, row_or_term_index, strict);
TRACE("try_add_bound", m_lar_solver.print_implied_bound(found_bound, tout););
}
} else {
m_improved_lower_bounds[j] = m_ibounds.size();
m_ibounds.push_back(implied_bound(v, j, is_low, coeff_before_j_is_pos, row_or_term_index, strict));
TRACE("try_add_bound", m_lar_solver.print_implied_bound(m_ibounds.back(), tout););
}
} else { // the upper bound case
if (try_get_value(m_improved_upper_bounds, j, k)) {
auto & found_bound = m_ibounds[k];
if (v < found_bound.m_bound || (v == found_bound.m_bound && found_bound.m_strict == false && strict)) {
found_bound = implied_bound(v, j, is_low, coeff_before_j_is_pos, row_or_term_index, strict);
TRACE("try_add_bound", m_lar_solver.print_implied_bound(found_bound, tout););
}
} else {
m_improved_upper_bounds[j] = m_ibounds.size();
m_ibounds.push_back(implied_bound(v, j, is_low, coeff_before_j_is_pos, row_or_term_index, strict));
TRACE("try_add_bound", m_lar_solver.print_implied_bound(m_ibounds.back(), tout););
}
}
}
}