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tweaking local search

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-03-02 10:18:12 -08:00
parent a37dfd3ab9
commit 40df1949f5
5 changed files with 74 additions and 44 deletions
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87
src/sat/sat_local_search.cpp
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@ -64,10 +64,8 @@ namespace sat {
}
void local_search::init_cur_solution() {
//cur_solution.resize(num_vars() + 1, false);
for (unsigned v = 1; v < num_vars(); ++v) {
for (unsigned v = 0; v < num_vars(); ++v) {
cur_solution[v] = (m_rand() % 2 == 1);
//std::cout << cur_solution[v] << '\n';
}
}
@ -172,6 +170,14 @@ namespace sat {
best_objective_value = objective_value;
}
}
bool local_search::all_objectives_are_met() const {
for (unsigned i = 0; i < ob_constraint.size(); ++i) {
bool_var v = ob_constraint[i].var_id;
if (!cur_solution[v]) return false;
}
return true;
}
void local_search::verify_solution() const {
for (unsigned i = 0; i < m_constraints.size(); ++i) {
@ -179,14 +185,19 @@ namespace sat {
}
}
void local_search::verify_constraint(constraint const& c) const {
unsigned local_search::constraint_value(constraint const& c) const {
unsigned value = 0;
for (unsigned i = 0; i < c.size(); ++i) {
value += is_true(c[i]) ? 1 : 0;
}
return value;
}
void local_search::verify_constraint(constraint const& c) const {
unsigned value = constraint_value(c);
if (c.m_k < value) {
display(std::cout << "violated constraint: ", c);
std::cout << "value: " << value << "\n";
IF_VERBOSE(0, display(verbose_stream() << "violated constraint: ", c);
verbose_stream() << "value: " << value << "\n";);
UNREACHABLE();
}
}
@ -319,10 +330,6 @@ namespace sat {
bool_var flipvar;
timer timer;
timer.start();
// ################## start ######################
IF_VERBOSE(1, verbose_stream() << "Unsat stack size: " << m_unsat_stack.size() << "\n";);
//std::cout << "Start initialize and local search, restart in every " << max_steps << " steps\n";
//std::cout << num_vars() << '\n';
unsigned tries, step = 0;
for (tries = 1; m_limit.inc() && !m_unsat_stack.empty(); ++tries) {
reinit();
@ -336,29 +343,37 @@ namespace sat {
}
flipvar = pick_var();
flip(flipvar);
m_vars[flipvar].m_time_stamp = step;
//if (!m_limit.inc()) break;pick_flip();
}
IF_VERBOSE(1, if (tries % 10 == 0) verbose_stream() << "(sat-local :tries " << tries << " :steps " << (tries - 1) * max_steps + step
<< " :unsat " << m_unsat_stack.size() << " :time " << timer.get_seconds() << ")\n";);
// the following is for tesing
IF_VERBOSE(1, if (tries % 10 == 0)
verbose_stream() << "(sat-local-search"
<< " :tries " << tries
<< " :steps " << (tries - 1) * max_steps + step
<< " :unsat " << m_unsat_stack.size()
<< " :time " << timer.get_seconds() << ")\n";);
// tell the SAT solvers about the phase of variables.
//if (m_par && tries % 10 == 0) {
//m_par->set_phase(*this);
if (m_par && tries % 10 == 0) {
m_par->set_phase(*this);
}
}
// remove unit clauses from assumptions.
m_constraints.shrink(num_constraints);
//print_solution();
if (m_unsat_stack.empty() && ob_constraint.empty()) { // or all variables in ob_constraint are true
TRACE("sat", display(tout););
lbool result;
if (m_unsat_stack.empty() && all_objectives_are_met()) {
verify_solution();
extract_model();
return l_true;
result = l_true;
}
// TBD: adjust return status
return l_undef;
else {
result = l_undef;
}
IF_VERBOSE(1, verbose_stream() << "(sat-local-search " << result << ")\n";);
return result;
}
@ -589,17 +604,18 @@ namespace sat {
exit(-1);
}
/*std::cout << "seed:\t" << m_config.seed() << '\n';
std::cout << "cutoff time:\t" << m_config.cutoff_time() << '\n';
std::cout << "strategy id:\t" << m_config.strategy_id() << '\n';
std::cout << "best_known_value:\t" << m_config.best_known_value() << '\n';
std::cout << "max_steps:\t" << max_steps << '\n';
*/
TRACE("sat",
tout << "seed:\t" << m_config.seed() << '\n';
tout << "cutoff time:\t" << m_config.cutoff_time() << '\n';
tout << "strategy id:\t" << m_config.strategy_id() << '\n';
tout << "best_known_value:\t" << m_config.best_known_value() << '\n';
tout << "max_steps:\t" << max_steps << '\n';
);
}
void local_search::print_info() {
for (unsigned v = 1; v < num_vars(); ++v) {
std::cout << v << "\t" << m_vars[v].m_neighbors.size() << '\t' << cur_solution[v] << '\t' << conf_change(v) << '\t' << score(v) << '\t' << slack_score(v) << '\n';
void local_search::print_info(std::ostream& out) {
for (unsigned v = 0; v < num_vars(); ++v) {
out << "v" << v << "\t" << m_vars[v].m_neighbors.size() << '\t' << cur_solution[v] << '\t' << conf_change(v) << '\t' << score(v) << '\t' << slack_score(v) << '\n';
}
}
@ -614,11 +630,11 @@ namespace sat {
for (unsigned i = 0; i < m_constraints.size(); ++i) {
constraint const& c = m_constraints[i];
display(out, c);
}
}
}
void local_search::display(std::ostream& out, constraint const& c) const {
out << c.m_literals << " <= " << c.m_k << "\n";
out << c.m_literals << " <= " << c.m_k << " lhs value: " << constraint_value(c) << "\n";
}
void local_search::display(std::ostream& out, unsigned v, var_info const& vi) const {
@ -644,4 +660,9 @@ namespace sat {
return false;
}
}
void local_search::set_phase(bool_var v, bool f) {
std::cout << v << " " << f << "\n";
}
}