int init_lookahead_procedure()
{
#ifndef LONG_LOOK
forced_literals = 0;
#endif
lastChanged = 0;
currentTimeStamp = 2;
/*
#ifdef COMPLEXDIFF
#ifdef EQ
if( !non_tautological_equivalences && !kSAT_flag ) ComputeDiffWeights();
#else
ComputeDiffWeights();
#endif
#endif
*/
#ifdef PLOT
sum_plot = 0;
count_plot = 0;
#endif
#ifdef INTELLOOK
if( treebased_lookahead() == UNSAT ) return UNSAT;
#else
tree_elements = 2 * lookaheadArrayLength;
#endif
#ifdef DL_DECREASE
DL_decrease = pow( DL_DECREASE, 1.0 / ((double) tree_elements ) );
#endif
return SAT;
}
int tree_lookahead()
{
int i, _forced_literals, _hyper_bins;
struct treeNode _treeNode, *_treeArray;
forced_literals = 0;
hyper_bins = 0;
lastChanged = 0;
init_lookahead_procedure();
if( treebased_lookahead() == UNSAT ) return UNSAT;
#ifdef ITERATE_LOOKAHEAD
do
{
_forced_literals = forced_literals;
_hyper_bins = hyper_bins;
if( depth == 0 )
{
// for( i = 1; i <= nrofvars; i++ ) { hyperTRD[ i ] = 0; hyperTRD[ -i ] = 0; }
// transitive_red( );
// transitive_reduction( );
// clean_bImp();
lastChanged = 0;
}
#endif
_treeArray = treeArray;
for( i = tree_elements-1; i >= 0; i-- )
{
_treeNode = *(_treeArray++);
if( _treeNode.literal == lastChanged )
{
if( depth == 0 ) printf("c found %i NHBRs\n", hyper_bins );
return SAT;
}
currentTimeStamp += _treeNode.gap;
if( currentTimeStamp >= LOOK_MAX )
{
currentTimeStamp -= _treeNode.gap; // is dit nodig?
return SAT;
}
if( treelookvar(_treeNode.literal) == UNSAT )
{
if( depth == 0 ) printf("c found %i NHBRs\n", hyper_bins );
return UNSAT;
}
currentTimeStamp -= _treeNode.gap;
if( forced_literals > _forced_literals )
{
if( IS_FIXED( _treeNode.literal ) && ( Rank[NR(_treeNode.literal)] < Rank_trigger) )
{
Rank_trigger = Rank[NR(_treeNode.literal)];
printf("c forced var with Rank %i\n", Rank_trigger );
}
_forced_literals = forced_literals; lastChanged = _treeNode.literal;
}
if( (depth == 0) && (hyper_bins > _hyper_bins) )
{
_hyper_bins = hyper_bins;
lastChanged = _treeNode.literal;
}
}
#ifdef ITERATE_LOOKAHEAD
currentTimeStamp += 2 * tree_elements;
if( (depth == 0) && (lastChanged != 0) )
{
if( treebased_lookahead() == UNSAT )
return UNSAT;
}
}
while( lastChanged != 0 );
#endif
if( depth == 0 ) printf("c found %i NHBRs\n", hyper_bins );
return SAT;
}
