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fix local search encoding bug

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2018-02-08 07:27:32 -08:00
parent 615e1e0845
commit 5e482def18
8 changed files with 78 additions and 63 deletions
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67
src/sat/sat_local_search.cpp
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@ -104,7 +104,7 @@ namespace sat {
coeff_vector& falsep = m_vars[v].m_watch[!is_true];
for (unsigned i = 0; i < falsep.size(); ++i) {
constraint& c = m_constraints[falsep[i].m_constraint_id];
SASSERT(falsep[i].m_coeff == 1);
//SASSERT(falsep[i].m_coeff == 1);
// will --slack
if (c.m_slack <= 0) {
dec_slack_score(v);
@ -113,7 +113,7 @@ namespace sat {
}
}
for (unsigned i = 0; i < truep.size(); ++i) {
SASSERT(truep[i].m_coeff == 1);
//SASSERT(truep[i].m_coeff == 1);
constraint& c = m_constraints[truep[i].m_constraint_id];
// will --true_terms_count[c]
// will ++slack
@ -139,7 +139,8 @@ namespace sat {
void local_search::reinit() {
if (!m_is_pb) {
IF_VERBOSE(10, verbose_stream() << "(sat-local-search reinit)\n";);
if (true || !m_is_pb) {
//
// the following methods does NOT converge for pseudo-boolean
// can try other way to define "worse" and "better"
@ -156,8 +157,7 @@ namespace sat {
}
}
for (unsigned i = 0; i < m_constraints.size(); ++i) {
constraint& c = m_constraints[i];
for (constraint & c : m_constraints) {
c.m_slack = c.m_k;
}
@ -216,31 +216,43 @@ namespace sat {
}
void local_search::verify_solution() const {
for (unsigned i = 0; i < m_constraints.size(); ++i) {
verify_constraint(m_constraints[i]);
}
for (constraint const& c : m_constraints)
verify_constraint(c);
}
void local_search::verify_unsat_stack() const {
for (unsigned i = 0; i < m_unsat_stack.size(); ++i) {
constraint const& c = m_constraints[m_unsat_stack[i]];
void local_search::verify_unsat_stack() const {
for (unsigned i : m_unsat_stack) {
constraint const& c = m_constraints[i];
SASSERT(c.m_k < constraint_value(c));
}
}
unsigned local_search::constraint_coeff(constraint const& c, literal l) const {
for (auto const& pb : m_vars[l.var()].m_watch[is_pos(l)]) {
if (pb.m_constraint_id == c.m_id) return pb.m_coeff;
}
UNREACHABLE();
return 0;
}
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;
literal t = c[i];
if (is_true(t)) {
value += constraint_coeff(c, t);
}
}
return value;
}
void local_search::verify_constraint(constraint const& c) const {
unsigned value = constraint_value(c);
IF_VERBOSE(11, display(verbose_stream() << "verify ", c););
TRACE("sat", display(verbose_stream() << "verify ", c););
if (c.m_k < value) {
IF_VERBOSE(0, display(verbose_stream() << "violated constraint: ", c);
verbose_stream() << "value: " << value << "\n";);
IF_VERBOSE(0, display(verbose_stream() << "violated constraint: ", c) << "value: " << value << "\n";);
UNREACHABLE();
}
}
@ -252,7 +264,7 @@ namespace sat {
// ~c <= k
void local_search::add_cardinality(unsigned sz, literal const* c, unsigned k) {
unsigned id = m_constraints.size();
m_constraints.push_back(constraint(k));
m_constraints.push_back(constraint(k, id));
for (unsigned i = 0; i < sz; ++i) {
m_vars.reserve(c[i].var() + 1);
literal t(~c[i]);
@ -264,14 +276,15 @@ namespace sat {
}
}
// c * coeffs <= k
void local_search::add_pb(unsigned sz, literal const* c, unsigned const* coeffs, unsigned k) {
unsigned id = m_constraints.size();
m_constraints.push_back(constraint(k));
m_constraints.push_back(constraint(k, id));
for (unsigned i = 0; i < sz; ++i) {
m_vars.reserve(c[i].var() + 1);
literal t(~c[i]);
literal t(c[i]);
m_vars[t.var()].m_watch[is_pos(t)].push_back(pbcoeff(id, coeffs[i]));
m_constraints.back().push(t); // add coefficient to constraint?
m_constraints.back().push(t);
}
if (sz == 1 && k == 0) {
m_vars[c[0].var()].m_bias = c[0].sign() ? 0 : 100;
@ -359,7 +372,7 @@ namespace sat {
lits.reset();
coeffs.reset();
for (unsigned j = 0; j < n; ++j) lits.push_back(~c[j]), coeffs.push_back(1);
for (literal l : c) lits.push_back(~l), coeffs.push_back(1);
lits.push_back(c.lit()); coeffs.push_back(k);
add_pb(lits.size(), lits.c_ptr(), coeffs.c_ptr(), n);
}
@ -889,21 +902,27 @@ namespace sat {
}
}
void local_search::display(std::ostream& out) const {
std::ostream& local_search::display(std::ostream& out) const {
for (constraint const& c : m_constraints) {
display(out, c);
}
for (bool_var v = 0; v < num_vars(); ++v) {
display(out, v, m_vars[v]);
}
return out;
}
void local_search::display(std::ostream& out, constraint const& c) const {
out << c.m_literals << " <= " << c.m_k << " lhs value: " << constraint_value(c) << "\n";
std::ostream& local_search::display(std::ostream& out, constraint const& c) const {
for (literal l : c) {
unsigned coeff = constraint_coeff(c, l);
if (coeff > 1) out << coeff << " * ";
out << l << " ";
}
return out << " <= " << c.m_k << " lhs value: " << constraint_value(c) << "\n";
}
void local_search::display(std::ostream& out, unsigned v, var_info const& vi) const {
out << "v" << v << " := " << (vi.m_value?"true":"false") << " bias: " << vi.m_bias << "\n";
std::ostream& local_search::display(std::ostream& out, unsigned v, var_info const& vi) const {
return out << "v" << v << " := " << (vi.m_value?"true":"false") << " bias: " << vi.m_bias << "\n";
}
bool local_search::check_goodvar() {