z3-z3-4.13.0.src.math.lp.random_updater_def.h Maven / Gradle / Ivy
The newest version!
/*++
Copyright (c) 2017 Microsoft Corporation
Module Name:
Abstract:
Author:
Lev Nachmanson (levnach)
Revision History:
--*/
#pragma once
#include "math/lp/random_updater.h"
#include "math/lp/static_matrix.h"
#include "math/lp/lar_solver.h"
#include "util/vector.h"
namespace lp {
random_updater::random_updater(
lar_solver & lar_solver,
const vector & column_indices) :
m_lar_solver(lar_solver),
m_range(100000) {
for (unsigned j : column_indices)
m_var_set.insert(j);
TRACE("lar_solver_rand", tout << "size = " << m_var_set.size() << "\n";);
}
bool random_updater::shift_var(unsigned j) {
SASSERT(!m_lar_solver.column_is_fixed(j) && !m_lar_solver.is_base(j));
bool ret = m_lar_solver.get_int_solver()->shift_var(j, m_range);
if (ret) {
const auto & A = m_lar_solver.A_r();
for (const auto& c : A.m_columns[j]) {
unsigned k = m_lar_solver.r_basis()[c.var()];
if (m_var_set.contains(k))
m_var_set.remove(k);
}
}
return ret;
}
void random_updater::update() {
// VERIFY(m_lar_solver.check_feasible());
unsigned_vector columns;
// m_var_set is going to change during the loop, make a copy
for (unsigned j : m_var_set) {
columns.push_back(j);
}
for (auto j : columns) {
if (!m_var_set.contains(j)) {
TRACE("lar_solver_rand", tout << "skipped " << j << "\n";);
continue;
}
if (!m_lar_solver.is_base(j))
shift_var(j);
else {
unsigned row_index = m_lar_solver.r_heading()[j];
for (auto & row_c : m_lar_solver.get_row(row_index)) {
unsigned cj = row_c.var();
if (!m_lar_solver.is_base(cj) &&
!m_lar_solver.column_is_fixed(cj) &&
shift_var(cj))
break; // done with the basic var j
}
}
}
TRACE("lar_solver_rand", tout << "m_var_set.size() = " << m_var_set.size() << "\n";);
}
}