/* * call-seq: * solver.simplify_db -> true or false * * Deprecated. The same as Solver#simplify. * */ static VALUE solver_simplify_db(VALUE rslv) { return solver_simplify(rslv); }
static lbool solver_search(solver* s, int nof_conflicts, int nof_learnts) { int* levels = s->levels; double var_decay = 0.95; double clause_decay = 0.999; double random_var_freq = 0.02; int conflictC = 0; veci learnt_clause; assert(s->root_level == solver_dlevel(s)); s->stats.starts++; s->var_decay = (float)(1 / var_decay ); s->cla_decay = (float)(1 / clause_decay); veci_resize(&s->model,0); veci_new(&learnt_clause); for (;;){ clause* confl = solver_propagate(s); if (confl != 0){ /* CONFLICT */ int blevel; #ifdef VERBOSEDEBUG printf(L_IND"**CONFLICT**\n", L_ind); #endif s->stats.conflicts++; conflictC++; if (solver_dlevel(s) == s->root_level){ veci_delete(&learnt_clause); return l_False; } veci_resize(&learnt_clause,0); solver_analyze(s, confl, &learnt_clause); blevel = veci_size(&learnt_clause) > 1 ? levels[lit_var(veci_begin(&learnt_clause)[1])] : s->root_level; blevel = s->root_level > blevel ? s->root_level : blevel; solver_canceluntil(s,blevel); solver_record(s,&learnt_clause); act_var_decay(s); act_clause_decay(s); }else{ /* NO CONFLICT */ int next; if (nof_conflicts >= 0 && conflictC >= nof_conflicts){ /* Reached bound on number of conflicts: */ s->progress_estimate = solver_progress(s); solver_canceluntil(s,s->root_level); veci_delete(&learnt_clause); return l_Undef; } if (solver_dlevel(s) == 0) /* Simplify the set of problem clauses: */ solver_simplify(s); if (nof_learnts >= 0 && vecp_size(&s->learnts) - s->qtail >= nof_learnts) /* Reduce the set of learnt clauses: */ solver_reducedb(s); /* New variable decision: */ s->stats.decisions++; next = order_select(s,(float)random_var_freq); if (next == var_Undef){ /* Model found: */ lbool* values = s->assigns; int i; for (i = 0; i < s->size; i++) veci_push(&s->model,(int)values[i]); solver_canceluntil(s,s->root_level); veci_delete(&learnt_clause); /* veci apa; veci_new(&apa); for (i = 0; i < s->size; i++) veci_push(&apa,(int)(s->model.ptr[i] == l_True ? toLit(i) : lit_neg(toLit(i)))); printf("model: "); printlits((lit*)apa.ptr, (lit*)apa.ptr + veci_size(&apa)); printf("\n"); veci_delete(&apa); */ return l_True; } assume(s,lit_neg(toLit(next))); } } #if 0 /* by mao; unreachable code */ return l_Undef; /* cannot happen */ #endif }