/
SATPreprocessor.cpp
1065 lines (1022 loc) · 29.2 KB
/
SATPreprocessor.cpp
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/////////////////
// OS Includes
#include <memory.h>
#include <stdlib.h>
//////////////
// Includes
#include "Clause.h"
#include "Debug.h"
#include "SATSolver.h"
#include "SATInstance.h"
#include "SATSolver.h"
#include "VariableList.h"
#include "VariableSet.h"
/////////////
// Defines
#define MAX_CLAUSE_LENGTH 3
///////////////////////////
// Static Initialization
//////////////////////////////////////////////////////////////////////////////////////////////////
// Public Methods
void SATSolver::vIncorporateLearnedClauses()
{
// Incorporate any clauses that were learned from the previous run into the SAT instance.
for (int i=0; i<_xLearnedClauses.iClauseCount(); i++) {
_pInstance->vAddClause(_xLearnedClauses.pClause(i));
}
_xLearnedClauses.vClear();
}
boolean SATSolver::bPreprocess(int iLevel_, int iIterationBound_)
{
time(&_iElapsedTime);
_iLastCheckTime = _iElapsedTime;
if (iLevel_ == 0)
return 0;
// Preprocesses the instance. Returns 1 if instance is unsatisfiable.
if (!_bInitialize()) {
_vCleanup();
return 1;
}
if (iIterationBound_ == -1) {
iIterationBound_ = 99999; // -1 implies no bound
}
int iInitialClauseCount = _pInstance->iClauseCount();
_pSet0 = new VariableSet(_iVariableCount);
_pSet1 = new VariableSet(_iVariableCount);
int iInitialCount = _pInstance->iClauseCount();
int iIteration = 0;
xOutputStream << "c Processing instance: sorting clauses..." << flush;
_pInstance->vSortClausesByLength();
xOutputStream << "\nc removing redundancies..." << flush;
int iClausesRemoved = 0;
int i;
for (i=1; i<_pInstance->iClauseCount(); i++) {
Clause* pCheck = _pInstance->pClause(i);
if (pCheck->bIsEqual(*(_pInstance->pClause(i-1)))) {
pCheck->vFlagAsDeleted(); // duplicate clause
iClausesRemoved++;
}
}
_vRemoveRedundancies(0, iClausesRemoved);
xOutputStream << iClausesRemoved << " redundant clauses eliminated." << flush;
_vCleanClauseLists();
boolean bContinue;
do {
bContinue = 0;
xOutputStream << "\nc unit reducing..." << flush;
int iNewUnaryClauses;
if (_bUnitReduce(iNewUnaryClauses)) {
_vCleanup(_iElapsedTime, iInitialClauseCount);
_vCleanup();
return 1;
}
xOutputStream << iNewUnaryClauses << " unary clauses identified." << flush;
if (iNewUnaryClauses) {
//bContinue = 1; Not needed since unary reduction goes until completion
_vCleanClauseLists();
}
int iBinaryClauses = 0;
if (iLevel_ > 1 && iLevel_ != 4) {
xOutputStream << "\nc binary inferring..." << flush;
if (_bBinaryInfer(iBinaryClauses)) {
_vCleanup(_iElapsedTime, iInitialClauseCount);
_vCleanup();
return 1;
}
xOutputStream << iBinaryClauses << " unary+binary clauses identified." << flush;
if (iBinaryClauses) {
bContinue = 1;
_vCleanClauseLists();
}
}
// END TEMP
xOutputStream << "\nc resolving..." << flush;
iBinaryClauses = 0;
if (iLevel_ != 4 && _bResolve(iBinaryClauses)) {
_vCleanup(_iElapsedTime, iInitialClauseCount);
_vCleanup();
return 1;
}
xOutputStream << iBinaryClauses << " resolutions performed." << flush;
if (iBinaryClauses) {
bContinue = 1;
_vCleanClauseLists();
}
if (iLevel_ > 2) {
xOutputStream << "\nc reducing clauses..." << flush;
iBinaryClauses = 0;
if (_bReduceClauses(iBinaryClauses)) {
_vCleanup(_iElapsedTime, iInitialClauseCount);
_vCleanup();
return 1;
}
xOutputStream << iBinaryClauses << " clauses reduced." << flush;
if (iBinaryClauses) {
bContinue = 1;
_vCleanClauseLists();
}
}
if (_bTimeLimitExpired()) {
xOutputStream << "\nc Preprocessing phase timeout." << endl;
return 0;
}
} while (bContinue && ++iIteration < iIterationBound_);
_vCleanup(_iElapsedTime, iInitialClauseCount);
_vCleanup();
return 0;
}
//////////////////////////////////////////////////////////////////////////////////////////////////
// Private/Protected Methods
void SATSolver::_vCleanClauseLists()
{
for (int i=0; i<_iVariableCount; i++) {
_aVariableStruct[i].xPositiveClauses.vRemoveDeletedClauses();
_aVariableStruct[i].xNegativeClauses.vRemoveDeletedClauses();
}
}
void SATSolver::_vCleanup(time_t iStart_, int iInitialClauseCount)
{
xOutputStream << "\nc Processing phase stats: " << endl;
xOutputStream << "c Initial clause count : " << iInitialClauseCount << endl;
_pInstance->vDestroyDeletedClauses();
xOutputStream << "c New clause count : "
<< _pInstance->iClauseCount()
<< endl;
time_t iEnd;
time(&iEnd);
xOutputStream << "c Seconds elapsed (real time): " << iEnd - iStart_ << " seconds." << endl;
delete _pSet0;
delete _pSet1;
}
boolean SATSolver::_bRedundancyCheck(Clause* pNewClause_)
{
Clause** pStart;
Clause** pEnd;
for (int i=0; i<pNewClause_->iVariableCount(); i++) {
VariableID iVar = pNewClause_->eConstrainedVariable(i);
ClauseList* pCheckList;
if (pNewClause_->iIsNegated(i)) {
pStart = _aVariableStruct[iVar].xNegativeClauses.pEntry(0);
pEnd = _aVariableStruct[iVar].xNegativeClauses.pLastEntry();
}
else {
pStart = _aVariableStruct[iVar].xPositiveClauses.pEntry(0);
pEnd = _aVariableStruct[iVar].xPositiveClauses.pLastEntry();
}
for (; pStart < pEnd; pStart++) {
if (*pStart != pNewClause_ && !(*pStart)->bIsDeleted()) {
switch(_iRedundancyCheck(pNewClause_, *pStart)) {
case 1:
delete pNewClause_; // clause is redundant.
//xOutputStream << "Redundant because of: "; (*pStart)->vOutput(); xOutputStream << endl;
return 1;
case 2:
//xOutputStream << "Redundant clause found: "; (*pStart)->vOutput(); xOutputStream << endl;
if (!(*pStart)->bLearned()) {
pNewClause_->vMakeRequired();
}
(*pStart)->vFlagAsDeleted();
}
}
}
}
return 0;
}
void SATSolver::_vOneSidedRedundancyCheck(Clause* pClause_, int& iClausesRemoved_)
{
// Check only if pClause_ makes other clauses redundant.
Clause** pStart;
Clause** pEnd;
//for (int i=0; i<pClause_->iVariableCount(); i++) {
//VariableID iVar = pClause_->eConstrainedVariable(i);
VariableID iVar = pClause_->eConstrainedVariable(0);
ClauseList* pCheckList;
//if (pClause_->iIsNegated(i)) {
if (pClause_->iIsNegated(0)) {
pStart = _aVariableStruct[iVar].xNegativeClauses.pEntry(0);
pEnd = _aVariableStruct[iVar].xNegativeClauses.pLastEntry();
}
else {
pStart = _aVariableStruct[iVar].xPositiveClauses.pEntry(0);
pEnd = _aVariableStruct[iVar].xPositiveClauses.pLastEntry();
}
for (; pStart < pEnd; pStart++) {
if (*pStart != pClause_ && !(*pStart)->bIsDeleted()) {
if(_bMakesRedundant(pClause_, *pStart)) {
(*pStart)->vFlagAsDeleted();
++iClausesRemoved_;
}
}
}
//}
}
int SATSolver::_iRedundancyCheck(Clause* pClause1_, Clause* pClause2_)
{
// Returns 1 if pClause1_ is redundant, and 2 if pClause2_ is redundant.
// Returns 0 otherwise
_pSet0->vClear();
_pSet1->vClear();
int i;
boolean bSwap;
if (pClause1_->iVariableCount() < pClause2_->iVariableCount()) {
bSwap = 1;
Clause* pTemp = pClause1_;
pClause1_ = pClause2_;
pClause2_ = pTemp;
}
else {
bSwap = 0;
}
for (i=0; i<pClause1_->iVariableCount(); i++) {
if (pClause1_->iIsNegated(i)) {
_pSet0->vAddVariableNoCheck(pClause1_->eConstrainedVariable(i));
}
else {
_pSet1->vAddVariableNoCheck(pClause1_->eConstrainedVariable(i));
}
}
for (i=0; i<pClause2_->iVariableCount(); i++) {
if (pClause2_->iIsNegated(i)) {
if (!_pSet0->bHasVariable(pClause2_->eConstrainedVariable(i))) {
return 0;
}
}
else {
if (!_pSet1->bHasVariable(pClause2_->eConstrainedVariable(i))) {
return 0;
}
}
}
// pClause1 is redundant!
if (bSwap) {
return 2;
}
return 1;
}
boolean SATSolver::_bMakesRedundant(Clause* pClause1_, Clause* pClause2_)
{
// Returns 1 if pClause2_ is redundant because of pClause1_
// Returns 0 otherwise.
// Does not detect duplicate clauses.
// Assumes variables of each clause are sorted.
assert(pClause1_->iVariableCount()); // assumes no null clause
if (pClause2_->iVariableCount() <= pClause1_->iVariableCount()) {
return 0;
}
int iDiff = 0;
int i = 0;
while (1) {
if (pClause1_->eConstrainedLiteral(i) == pClause2_->eConstrainedLiteral(iDiff)) {
i++;
if (i == pClause1_->iVariableCount()) {
return 1;
}
}
iDiff++;
if (iDiff == pClause2_->iVariableCount()) {
return 0;
}
}
}
boolean SATSolver::_bResolve(Clause* pClause_, int& iCount_)
{
// returns 1 if contradiction derived
int i;
Clause** pStart;
Clause** pEnd;
for (i=0; i<pClause_->iVariableCount(); i++) {
VariableID iVar = pClause_->eConstrainedVariable(i);
ClauseList* pCheckList;
if (pClause_->iIsNegated(i)) {
pStart = _aVariableStruct[iVar].xPositiveClauses.pEntry(0);
pEnd = _aVariableStruct[iVar].xPositiveClauses.pLastEntry();
}
else {
pStart = _aVariableStruct[iVar].xNegativeClauses.pEntry(0);
pEnd = _aVariableStruct[iVar].xNegativeClauses.pLastEntry();
}
for (; pStart < pEnd; pStart++) {
Clause* pCompare = *pStart;
if (pCompare != pClause_ && !pCompare->bIsDeleted()) {
Clause* pNewClause = _pResolve(pClause_, pCompare, iVar);
if (pNewClause) {
if (pNewClause->iVariableCount() == 0) {
// Instance is UNSAT
delete pNewClause;
return 1;
}
else if (!_bRedundancyCheck(pNewClause)) {
if (_bInitializeClause(pNewClause)) {
delete pNewClause;
return 1;
}
else {
iCount_++;
_pInstance->vAddClause(pNewClause);
}
}
if (pClause_->bIsDeleted()) {
return 0;
}
}
}
}
}
return 0;
}
Clause* SATSolver::_pResolve(Clause* pClause1_,
Clause* pClause2_,
VariableID iResolveVariable_)
{
int iMaximumLength;
if (pClause1_->iVariableCount() < pClause2_->iVariableCount()) {
iMaximumLength = pClause2_->iVariableCount() - 1;
}
else {
iMaximumLength = pClause1_->iVariableCount() - 1;
}
if (iMaximumLength < MAX_CLAUSE_LENGTH &&
pClause1_->iVariableCount() > 2 && pClause2_->iVariableCount() > 2) {
iMaximumLength = MAX_CLAUSE_LENGTH;
}
if (pClause1_->iVariableCount() == 2 && pClause2_->iVariableCount() == 2) {
return 0;
}
int i1 = 0;
int i2 = 0;
int iLength = 0;
while (iLength <= iMaximumLength+1) {
while (pClause1_->eConstrainedVariable(i1) < pClause2_->eConstrainedVariable(i2)) {
iLength++;
i1++;
if (i1 == pClause1_->iVariableCount()) {
iLength += pClause2_->iVariableCount() - i2;
goto done;
}
}
while (pClause1_->eConstrainedVariable(i1) > pClause2_->eConstrainedVariable(i2)) {
iLength++;
i2++;
if (i2 == pClause2_->iVariableCount()) {
iLength += pClause1_->iVariableCount() - i1;
goto done;
}
}
if (pClause1_->eConstrainedVariable(i1) == pClause2_->eConstrainedVariable(i2)) {
iLength++;
if (pClause1_->eConstrainedVariable(i1) != iResolveVariable_ &&
pClause1_->iIsNegated(i1) != pClause2_->iIsNegated(i2)) {
return 0; // tautology
}
i1++;
i2++;
if (i1 == pClause1_->iVariableCount()) {
iLength += pClause2_->iVariableCount() - i2;
goto done;
}
if (i2 == pClause2_->iVariableCount()) {
iLength += pClause1_->iVariableCount() - i1;
goto done;
}
}
}
done:
if (iLength-1 > iMaximumLength) {
return 0;
}
_pSet0->vClear();
_pSet1->vClear();
int i;
for (i=0; i<pClause1_->iVariableCount(); i++) {
VariableID iAddMe = pClause1_->eConstrainedVariable(i);
if (iAddMe != iResolveVariable_) {
if (pClause1_->iIsNegated(i)) {
_pSet0->vAddVariableNoCheck(iAddMe);
}
else {
_pSet1->vAddVariableNoCheck(iAddMe);
}
}
}
for (i=0; i<pClause2_->iVariableCount(); i++) {
VariableID iAddMe = pClause2_->eConstrainedVariable(i);
if (iAddMe != iResolveVariable_) {
if (pClause2_->iIsNegated(i)) {
_pSet0->vAddVariable(iAddMe);
}
else {
_pSet1->vAddVariable(iAddMe);
}
}
}
assert(_pSet1->iCount() + _pSet0->iCount() == iLength-1);
// up-casting to VariableList to keep xlC compiler happy:
Clause* pNew = new Clause(*(VariableList*)_pSet1, *(VariableList*)_pSet0, 1);
/* pClause1_->vOutput(xOutputStream);
cout << " and ";
pClause2_->vOutput(xOutputStream);
cout << " make: ";
pNew->vOutput(xOutputStream);
cout << endl;*/
pNew->vMakeLearned();
return pNew;
}
boolean SATSolver::_bResolve(int& iClausesResolved_)
{
int i;
for (i=0; i<_pInstance->iClauseCount(); i++) {
if (_bTimeLimitExpired()) {
xOutputStream << "timeout. ";
return 0;
}
if (_bPrintStackCheck()) {
double fPercent = ((double)i / (double)_pInstance->iClauseCount()) * 100.0;
xOutputStream << (int) fPercent << "%.." << flush;
}
Clause* pCheck = _pInstance->pClause(i);
if (!pCheck->bIsDeleted()) {
if (_bResolve(pCheck, iClausesResolved_)) {
return 1;
}
}
}
return 0;
}
boolean SATSolver::_bReduceClauses(int& iNewClauses_)
{
int i;
time(&_iLastCheckTime);
for (i=0; i<_pInstance->iClauseCount(); i++) {
if (_bTimeLimitExpired()) {
xOutputStream << "timeout. ";
return 0;
}
if (_bPrintStackCheck()) {
double fI = i;
double fT = _pInstance->iClauseCount();
double fPercent = (fI / fT) * 100.0;
xOutputStream << (int) fPercent << "%.." << flush;
}
Clause* pCheck = _pInstance->pClause(i);
if (!pCheck->bIsDeleted() && pCheck->iVariableCount() > 2) {
Clause* pNew = _pReduceClause(pCheck);
if (pNew) {
//xOutputStream << "Reduced clause: "; pNew->vOutput(); xOutputStream << endl;
//xOutputStream << "From: "; pCheck->vOutput(); xOutputStream << endl;
if (pCheck->bLearned()) {
pNew->vMakeLearned();
}
pCheck->vFlagAsDeleted(); // redundant
if (pNew->iVariableCount() == 0) {
// Instance is UNSAT
delete pNew;
return 1;
}
else {
boolean bResult = _bRedundancyCheck(pNew);
assert(bResult == 0);
if (_bInitializeClause(pNew)) {
delete pNew;
return 1;
}
iNewClauses_++;
_pInstance->vAddClause(pNew);
/*if (_bResolve(pNew)) {
return 1;
}*/
}
}
}
}
return 0;
}
boolean SATSolver::_bBinaryInfer(int& iNewClauses_)
{
if (_bUnitPropagate()) {
return 1;
}
int i;
double fI = 0.0;
double fT = ((double)_iVariableCount * (double)(_iVariableCount+1)) / 2.0;
time(&_iLastCheckTime);
for (i=0; i<_iVariableCount; i++) {
if (_bTimeLimitExpired()) {
xOutputStream << "timeout. ";
return 0;
}
if (_bPrintStackCheck()) {
double fPercent = (fI / fT) * 100.0;
xOutputStream << (int) fPercent << "%.." << flush;
}
if (!_aVariableStruct[i].pReason) {
//xOutputStream << "c Trying " << i << endl;
if (_aBinaryCount0[i]) {
if (_bBinaryReduce(i, 1, iNewClauses_))
return 1;
}
}
if (!_aVariableStruct[i].pReason) {
if (_aBinaryCount1[i]) {
if (_bBinaryReduce(i, 0, iNewClauses_))
return 1;
}
}
fI += _iVariableCount-i;
}
return 0;
}
Clause* SATSolver::_pReduceClause(Clause* pReduceMe_)
{
// See if unit propagation can derive a clause that makes
// this one redundant.
if (pReduceMe_->iVariableCount() < 3) {
return 0;
}
//xOutputStream << "Reducing: " ; pReduceMe_->vOutput(); xOutputStream << endl;
for (int i=0; i<pReduceMe_->iVariableCount(); i++) {
assert(_pUnitList->iCount() == 0);
for (int j=0; j<pReduceMe_->iVariableCount(); j++) {
if (j!=i) {
VariableID iVar = pReduceMe_->eConstrainedVariable(j);
if (!_aVariableStruct[iVar].pReason) {
_pUnitList->vAdd(iVar);
if (pReduceMe_->iIsNegated(j)) {
_aAssignment[iVar] = 1;
}
else {
_aAssignment[iVar] = 0;
}
}
}
}
if (_bFastUnitPropagate()) {
_pSet0->vClear();
_pSet1->vClear();
for (int k=0; k<pReduceMe_->iVariableCount(); k++) {
if (k!=i) {
VariableID iVar = pReduceMe_->eConstrainedVariable(k);
if (!_aVariableStruct[iVar].pReason) {
if (pReduceMe_->iIsNegated(k)) {
_pSet0->vAddVariableNoCheck(iVar);
}
else {
_pSet1->vAddVariableNoCheck(iVar);
}
}
}
} // for (int k
Clause* pReducedClause = new Clause(*(VariableList*)_pSet1, *(VariableList*)_pSet0, (int)1);
//pReducedClause->vOutput(); xOutputStream << endl;
//xOutputStream << '.' << flush;
return pReducedClause;
} // if (bFastUnitPropagate
}
return 0;
}
int SATSolver::_iFastUnitPropagate(VariableID& eUnitVar_)
{
int i;
VariableID eID;
VariableStruct* pWorkStruct;
Clause** pStart;
Clause** pEnd;
Clause** pBegin;
Clause* pReduceMe;
int j;
for (i=0; i<_pUnitList->iCount(); i++) {
eID = _pUnitList->iVariable(i);
pWorkStruct = &_aVariableStruct[eID];
if (_aAssignment[eID] == 0) {
pStart = pWorkStruct->xPositiveClauses.pEntry(0);
pEnd = pWorkStruct->xPositiveClauses.pLastEntry();
}
else {
assert(_aAssignment[eID] == 1);
pStart = pWorkStruct->xNegativeClauses.pEntry(0);
pEnd = pWorkStruct->xNegativeClauses.pLastEntry();
}
pBegin = pStart;
for (;pStart < pEnd; pStart++) {
pReduceMe = *pStart;
if (!pReduceMe->bIsSatisfied()) {
switch(pReduceMe->iReduce()) {
case 0:
// Contradiction!
for (; pStart >= pBegin; pStart--) {
(*pStart)->iExpand();
}
_vFastBackup(i);
return 1;
case 1:
for (j = 0; j < pReduceMe->iPermaCount(); j++) {
eID = pReduceMe->eConstrainedVariable(j);
if (_aAssignment[eID] == NON_VALUE) {
_pUnitList->vAdd(eID);
if (pReduceMe->iIsNegated(j)) {
_aAssignment[eID] = 0;
if (!_pNegativeBackup->bAddVariable(eID)) {
// found a unit var.
for (; pStart >= pBegin; pStart--) {
(*pStart)->iExpand();
}
_vFastBackup(i);
eUnitVar_ = eID;
return 3; // var is negated
}
}
else {
_aAssignment[eID] = 1;
if (!_pPositiveBackup->bAddVariable(eID)) {
// found a unit var.
for (; pStart >= pBegin; pStart--) {
(*pStart)->iExpand();
}
_vFastBackup(i);
eUnitVar_ = eID;
return 2; // var is positive
}
}
break;
}
}
}
}
} // for (;pStart...
} // for (i=..
_vFastBackupScore();
return 0;
}
boolean SATSolver::_bFastUnitPropagate()
{
int i;
VariableID eID;
VariableStruct* pWorkStruct;
Clause** pStart;
Clause** pEnd;
Clause** pBegin;
Clause* pReduceMe;
int j;
for (i=0; i<_pUnitList->iCount(); i++) {
eID = _pUnitList->iVariable(i);
pWorkStruct = &_aVariableStruct[eID];
if (_aAssignment[eID] == 0) {
pStart = pWorkStruct->xPositiveClauses.pEntry(0);
pEnd = pWorkStruct->xPositiveClauses.pLastEntry();
}
else {
assert(_aAssignment[eID] == 1);
pStart = pWorkStruct->xNegativeClauses.pEntry(0);
pEnd = pWorkStruct->xNegativeClauses.pLastEntry();
}
pBegin = pStart;
for (;pStart < pEnd; pStart++) {
pReduceMe = *pStart;
if (!pReduceMe->bIsSatisfied()) {
switch(pReduceMe->iReduce()) {
case 0:
// Contradiction!
for (; pStart >= pBegin; pStart--) {
(*pStart)->iExpand();
}
_vFastBackup(i);
return 1;
case 1:
for (j = 0; j < pReduceMe->iPermaCount(); j++) {
eID = pReduceMe->eConstrainedVariable(j);
if (_aAssignment[eID] == NON_VALUE) {
_pUnitList->vAdd(eID);
if (pReduceMe->iIsNegated(j)) {
_aAssignment[eID] = 0;
}
else {
_aAssignment[eID] = 1;
}
break;
}
}
}
}
} // for (;pStart...
} // for (i=..
_vFastBackupScore();
return 0;
}
void SATSolver::_vRemoveRedundancies(int iStartIndex_, int& iClausesRemoved_)
{
iClausesRemoved_ = 0;
int i;
for (i=iStartIndex_; i<_pInstance->iClauseCount(); i++) {
Clause* pCheck = _pInstance->pClause(i);
if (!pCheck->bIsDeleted()) {
_vOneSidedRedundancyCheck(pCheck, iClausesRemoved_);
}
if (_bTimeLimitExpired()) {
xOutputStream << "timeout. ";
return;
}
if (_bPrintStackCheck()) {
double fPercent = ((double)(i-iStartIndex_) /
(double)(_pInstance->iClauseCount()-iStartIndex_))
* 100.0;
xOutputStream << (int) fPercent << "%.." << flush;
}
}
}
boolean SATSolver::_bUnitReduce(int& iNewClauses_)
{
if (_bUnitPropagate()) {
return 1;
}
iNewClauses_ = 0;
boolean bAgain = 0;
VariableID eOtherUnitVar;
do {
bAgain = 0;
for (int i=0; i<_iVariableCount; i++) {
if (_bTimeLimitExpired()) {
xOutputStream << "timeout. ";
return 0;
}
if (_bPrintStackCheck()) {
// Is there a reasonable way to estimate % done?
xOutputStream << "." << flush;
}
VariableID iVar = i;
_pPositiveBackup->vClear();
_pNegativeBackup->vClear();
if (!_aVariableStruct[iVar].pReason) {
if (_aScore1[iVar] != -1 && _aBinaryCount1[iVar]) {
_pUnitList->vAdd(iVar);
_aAssignment[iVar] = 0;
int iResult = _iFastUnitPropagate(eOtherUnitVar);
assert(iResult < 2);
if (iResult) {
memset(_aScore0, 0, sizeof(int)*_iVariableCount);
memset(_aScore1, 0, sizeof(int)*_iVariableCount);
bAgain = 1;
_pSet0->vClear();
_pSet1->vClear();
_pSet1->vAddVariableNoCheck(iVar);
Clause* pNew = new Clause(*(VariableList*)_pSet1, *(VariableList*)_pSet0, (int)1);
_pInstance->vAddClause(pNew);
//xOutputStream << "New unary clause: "; pNew->vOutput(); xOutputStream << endl;
iNewClauses_++;
boolean bResult = _bRedundancyCheck(pNew);
assert(bResult == 0);
if (_bInitializeClause(pNew)) {
return 1;
}
/*if (_bResolve(pNew)) {
return 1;
}*/
if (_bUnitPropagate()) {
return 1;
}
}
}
}
if (!_aVariableStruct[iVar].pReason) {
if (_aScore0[iVar] != -1 && _aBinaryCount0[iVar]) {
_pUnitList->vAdd(iVar);
_aAssignment[iVar] = 1;
int iResult = _iFastUnitPropagate(eOtherUnitVar);
if (iResult) {
memset(_aScore0, 0, sizeof(*_aScore0)*_iVariableCount);
memset(_aScore1, 0, sizeof(*_aScore1)*_iVariableCount);
bAgain = 1;
_pSet0->vClear();
_pSet1->vClear();
switch(iResult) {
case 1:
_pSet0->vAddVariableNoCheck(iVar);
break;
case 2:
//xOutputStream << "Wheee!: " <<eOtherUnitVar << endl;
_pSet1->vAddVariableNoCheck(eOtherUnitVar);
break;
case 3:
//xOutputStream << "Wheee!: " <<eOtherUnitVar << endl;
_pSet0->vAddVariableNoCheck(eOtherUnitVar);
break;
}
Clause* pNew = new Clause(*(VariableList*)_pSet1, *(VariableList*)_pSet0, (int)1);
_pInstance->vAddClause(pNew);
//xOutputStream << "New unary clause: "; pNew->vOutput(); xOutputStream << endl;
iNewClauses_++;
boolean bResult = _bRedundancyCheck(pNew);
assert(bResult == 0);
if (_bInitializeClause(pNew)) {
return 1;
}
/*if (_bResolve(pNew)) {
return 1;
}*/
if (_bUnitPropagate()) {
return 1;
}
}
}
}
} // for
} while (bAgain);
memset(_aScore0, 0, sizeof(*_aScore0)*_iVariableCount);
memset(_aScore1, 0, sizeof(*_aScore1)*_iVariableCount);
return 0;
}
boolean SATSolver::_bBinaryReduce(VariableID eWith_, DomainValue lWhich_, int& iNewClauses_)
{
memcpy(_aScore0, _aBinaryCount0, sizeof(int)*_iVariableCount);
memcpy(_aScore1, _aBinaryCount1, sizeof(int)*_iVariableCount);
_aVariableStruct[eWith_].bBranch = 1;
assert(_aAssignment[eWith_] == NON_VALUE);
assert(!_aVariableStruct[eWith_].pReason);
if (lWhich_) {
_pUnitVariables1->vAddVariable(eWith_);
}
else {
_pUnitVariables0->vAddVariable(eWith_);
}
if (_bUnitPropagate()) {
_pBackupToFirstBranch();
assert(_aAssignment[eWith_] == NON_VALUE);
assert(_aVariableStruct[eWith_].bBranch == 0);
_pSet0->vClear();
_pSet1->vClear();
if (lWhich_) {
_pSet0->vAddVariableNoCheck(eWith_);
}
else {
_pSet1->vAddVariableNoCheck(eWith_);
}
Clause* pNew = new Clause(*(VariableList*)_pSet1, *(VariableList*)_pSet0, (int)1);
_pInstance->vAddClause(pNew);
//xOutputStream << "New unary clause: "; pNew->vOutput(); xOutputStream << endl;
iNewClauses_++;
boolean bResult = _bRedundancyCheck(pNew);
assert(bResult == 0);
if (_bInitializeClause(pNew)) {
return 1;
}
/*if (_bResolve(pNew)) {
return 1;
}*/
if (_bUnitPropagate()) {
return 1;
}
return 0;
}
VariableID eOtherUnitVar;
int i;
for (i=eWith_+1; i<_iVariableCount; i++) {
VariableID iVar = i;
//xOutputStream << _aBinaryCount0[iVar] + _aBinaryCount1[iVar] << endl;
_pPositiveBackup->vClear();
_pNegativeBackup->vClear();
if (!_aVariableStruct[iVar].pReason) {
if (_aScore1[iVar] != -1
//&& _aBinaryCount1[iVar]
&& _aBinaryCount1[iVar] > _aScore1[iVar]
) {
_pUnitList->vAdd(iVar);
_aAssignment[iVar] = 0;
if (_iFastUnitPropagate(eOtherUnitVar)) {
assert(_pUnitVariables0->iCount() == 0);
assert(_pUnitVariables0->iCount() == 0);
_pUnitVariables1->vAddVariableNoCheck(iVar);
if (_bUnitPropagate()) {
_pBackupToFirstBranch();
assert(_aAssignment[eWith_] == NON_VALUE);
assert(_aVariableStruct[eWith_].bBranch == 0);
_pSet0->vClear();
_pSet1->vClear();
if (lWhich_) {
_pSet0->vAddVariableNoCheck(eWith_);
}
else {
_pSet1->vAddVariableNoCheck(eWith_);
}
Clause* pNew = new Clause(*(VariableList*)_pSet1, *(VariableList*)_pSet0, (int)1);
_pInstance->vAddClause(pNew);
//xOutputStream << "New unary clause?!?!!?: "; pNew->vOutput(); xOutputStream << endl;
iNewClauses_++;
boolean bResult = _bRedundancyCheck(pNew);
assert(bResult == 0);
if (_bInitializeClause(pNew)) {
return 1;
}
if (_bUnitPropagate()) {
return 1;
}
return 0;
} // _bUnitPropagate
assert(_aAssignment[iVar] != NON_VALUE);
_pSet0->vClear();
_pSet1->vClear();
_pSet1->vAddVariableNoCheck(iVar);
if (lWhich_) {
_pSet0->vAddVariableNoCheck(eWith_);
}
else {
_pSet1->vAddVariableNoCheck(eWith_);
}
Clause* pNew = new Clause(*(VariableList*)_pSet1, *(VariableList*)_pSet0, (int)1);
_aVariableStruct[iVar].pReason = pNew;
//xOutputStream << "New binary clause: "; pNew->vOutput(); xOutputStream << endl;
_pInstance->vAddClause(pNew);
iNewClauses_++;
boolean bResult = _bRedundancyCheck(pNew);
assert(bResult == 0);
if (_bInitializeClause(pNew)) {
return 1;
}
pNew->vFudge();
memset(_aScore0, 0, sizeof(*_aScore0)*_iVariableCount);
memset(_aScore1, 0, sizeof(*_aScore1)*_iVariableCount);
} // _iFastUnitPropagate
}
if (!_aVariableStruct[iVar].pReason) {
if (_aScore0[iVar] != -1
//&& _aBinaryCount0[iVar]
&& _aBinaryCount0[iVar] > _aScore0[iVar]
) {
_pUnitList->vAdd(iVar);
_aAssignment[iVar] = 1;
int iResult = _iFastUnitPropagate(eOtherUnitVar);
if (iResult) {
assert(_pUnitVariables0->iCount() == 0);
assert(_pUnitVariables0->iCount() == 0);
_pSet0->vClear();
_pSet1->vClear();
switch(iResult) {
case 1:
_pSet0->vAddVariableNoCheck(iVar);
_pUnitVariables0->vAddVariableNoCheck(iVar);
eOtherUnitVar = iVar;
break;
case 2:
_pSet1->vAddVariableNoCheck(eOtherUnitVar);