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z3/src/util/lp/lp_bound_propagator.cpp
Christoph M. Wintersteiger d61b722b68 Partial cleanup of util/lp/*
2017-09-17 16:00:06 +01:00

68 lines
2.4 KiB
C++

/*++
Copyright (c) 2017 Microsoft Corporation
Module Name:
<name>
Abstract:
<abstract>
Author:
Lev Nachmanson (levnach)
Revision History:
--*/
#include "util/lp/lar_solver.h"
namespace lp {
lp_bound_propagator::lp_bound_propagator(lar_solver & ls):
m_lar_solver(ls) {}
column_type lp_bound_propagator::get_column_type(unsigned j) const {
return m_lar_solver.m_mpq_lar_core_solver.m_column_types()[j];
}
const impq & lp_bound_propagator::get_low_bound(unsigned j) const {
return m_lar_solver.m_mpq_lar_core_solver.m_r_low_bounds()[j];
}
const impq & lp_bound_propagator::get_upper_bound(unsigned j) const {
return m_lar_solver.m_mpq_lar_core_solver.m_r_upper_bounds()[j];
}
void lp_bound_propagator::try_add_bound(const mpq & v, unsigned j, bool is_low, bool coeff_before_j_is_pos, unsigned row_or_term_index, bool strict) {
unsigned term_j = m_lar_solver.adjust_column_index_to_term_index(j);
mpq w = v;
if (term_j != j) {
j = term_j;
w += m_lar_solver.get_term(term_j).m_v; // when terms are turned into the columns they "lose" the right side, at this moment they aquire it back
}
lconstraint_kind kind = is_low? GE : LE;
if (strict)
kind = static_cast<lconstraint_kind>(kind / 2);
if (!bound_is_interesting(j, kind, w))
return;
unsigned k; // index to ibounds
if (is_low) {
if (try_get_val(m_improved_low_bounds, j, k)) {
auto & found_bound = m_ibounds[k];
if (w > found_bound.m_bound || (w == found_bound.m_bound && found_bound.m_strict == false && strict))
found_bound = implied_bound(w, j, is_low, coeff_before_j_is_pos, row_or_term_index, strict);
} else {
m_improved_low_bounds[j] = m_ibounds.size();
m_ibounds.push_back(implied_bound(w, j, is_low, coeff_before_j_is_pos, row_or_term_index, strict));
}
} else { // the upper bound case
if (try_get_val(m_improved_upper_bounds, j, k)) {
auto & found_bound = m_ibounds[k];
if (w < found_bound.m_bound || (w == found_bound.m_bound && found_bound.m_strict == false && strict))
found_bound = implied_bound(w, j, is_low, coeff_before_j_is_pos, row_or_term_index, strict);
} else {
m_improved_upper_bounds[j] = m_ibounds.size();
m_ibounds.push_back(implied_bound(w, j, is_low, coeff_before_j_is_pos, row_or_term_index, strict));
}
}
}
}