latest updates from Cliff

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/sat/sat_local_search.cpp

@@ -37,10 +37,20 @@ namespace sat {
         var_neighbor.push_back(bool_var_vector());
 
         for (bool_var v = 1; v <= num_vars(); ++v) {
+			//std::cout << pos_var_term[v].size() << '\t' << neg_var_term[v].size() << '\n';
             bool_vector is_neighbor(num_vars() + 1, false);
             var_neighbor.push_back(bool_var_vector());
-            for (unsigned i = 0; i < var_term[v].size(); ++i) {
+            for (unsigned i = 0; i < pos_var_term[v].size(); ++i) {
-                unsigned c = var_term[v][i].constraint_id;
+                unsigned c = pos_var_term[v][i];
+                for (unsigned j = 0; j < constraint_term[c].size(); ++j) {
+                    bool_var w = constraint_term[c][j].var_id; 
+                    if (w == v || is_neighbor[w]) continue;
+                    is_neighbor[w] = true;
+                    var_neighbor.back().push_back(w);
+                }
+            }
+			for (unsigned i = 0; i < neg_var_term[v].size(); ++i) {
+				unsigned c = neg_var_term[v][i];
 				for (unsigned j = 0; j < constraint_term[c].size(); ++j) {
 					bool_var w = constraint_term[c][j].var_id;
 					if (w == v || is_neighbor[w]) continue;
@@ -84,10 +94,17 @@ namespace sat {
     // figure out variables scores and sscores
     void local_search::init_scores() {
         for (unsigned v = 1; v <= num_vars(); ++v) {
-            for (unsigned i = 0; i < var_term[v].size(); ++i) {
+			int_vector truep, falsep;
-                int c = var_term[v][i].constraint_id;
+			if (cur_solution[v]) {
-                if (cur_solution[v] != var_term[v][i].sense) {
+				truep = pos_var_term[v];
-                    // will ++true_terms_count[c]
+				falsep = neg_var_term[v];
+			}
+			else {
+				truep = neg_var_term[v];
+				falsep = pos_var_term[v];
+			}
+			for (unsigned i = 0; i < falsep.size(); ++i) {
+				int c = falsep[i];
 				// will --slack
 				if (constraint_slack[c] <= 0) {
 					--sscore[v];
@@ -95,7 +112,8 @@ namespace sat {
 						--m_var_info[v].m_score;
 				}
 			}
-                else { // if (cur_solution[v] == var_term[v][i].sense)
+			for (unsigned i = 0; i < truep.size(); ++i) {
+				int c = truep[i];
                 // will --true_terms_count[c]
                 // will ++slack
                 if (constraint_slack[c] <= -1) {
@@ -106,7 +124,6 @@ namespace sat {
             }
         }
     }
-    }
 
     // init goodvars 
     void local_search::init_goodvars() {
@@ -186,10 +203,13 @@ namespace sat {
             m_num_vars = std::max(c[i].var() + 1, m_num_vars);
             // var_term.reserve(c[i].var() + 1);
             term t;
-            t.constraint_id = id;
             t.var_id = c[i].var();
             t.sense =  c[i].sign();
-            var_term[t.var_id].push_back(t);
+			if (t.sense)
+				pos_var_term[t.var_id].push_back(id);
+			else
+				neg_var_term[t.var_id].push_back(id);
+            //var_term[t.var_id].push_back(t);
             constraint_term[id].push_back(t);
         }
         constraint_k.push_back(k);                
@@ -310,15 +330,16 @@ namespace sat {
                 flip(flipvar);
                 time_stamp[flipvar] = step;
             }
+            if (tries % 10 == 0) {
 				// take a look at watch
 				stop = clock();
 				elapsed_time = (double)(stop - start) / CLOCKS_PER_SEC;
-            if (tries % 10 == 0) 
 				std::cout << tries << ": " << elapsed_time << '\n';
+			}
             if (elapsed_time > cutoff_time)
                 reach_cutoff_time = true;
-            //if (reach_known_best_value || reach_cutoff_time)
+            if (reach_known_best_value || reach_cutoff_time)
-            //    break;
+                break;
         }
         if (reach_known_best_value) {
             std::cout << elapsed_time << "\n";
@@ -334,8 +355,6 @@ namespace sat {
 
     void local_search::flip(bool_var flipvar)
     {
-		static unsigned_vector hack_vector;
-		hack_vector.reset();
         // already changed truth value!!!!
         cur_solution[flipvar] = !cur_solution[flipvar];
 
@@ -343,12 +362,19 @@ namespace sat {
         int org_flipvar_score = score(flipvar);
         int org_flipvar_sscore = sscore[flipvar];
 
+		int_vector truep, falsep;
+		if (cur_solution[flipvar]) {
+			truep = pos_var_term[flipvar];
+			falsep = neg_var_term[flipvar];
+		}
+		else {
+			truep = neg_var_term[flipvar];
+			falsep = pos_var_term[flipvar];
+		}
+
         // update related clauses and neighbor vars
-        svector<term> const& constraints = var_term[flipvar];
+		for (unsigned i = 0; i < truep.size(); ++i) {
-        unsigned num_cs = constraints.size();
+			c = truep[i];
-        for (unsigned i = 0; i < num_cs; ++i) {
-            c = constraints[i].constraint_id;
-            if (cur_solution[flipvar] == constraints[i].sense) {
 			//++true_terms_count[c];
 			--constraint_slack[c];
 			switch (constraint_slack[c]) {
@@ -367,7 +393,6 @@ namespace sat {
 					++cscc[v];
 					//score[v] += constraint_weight[c];
 					++m_var_info[v].m_score;
-						hack_vector.push_back(v);
 					// slack increasing var
 					if (cur_solution[v] == constraint_term[c][j].sense)
 						++sscore[v];
@@ -389,7 +414,8 @@ namespace sat {
 				break;
 			}
 		}
-            else { // if (cur_solution[flipvar] != var_term[i].sense)
+		for (unsigned i = 0; i < falsep.size(); ++i) {
+			c = falsep[i];
 			//--true_terms_count[c];
 			++constraint_slack[c];
 			switch (constraint_slack[c]) {
@@ -400,7 +426,6 @@ namespace sat {
 					if (cur_solution[v] != constraint_term[c][j].sense) {
 						//score[v] += constraint_weight[c];
 						++m_var_info[v].m_score;
-							hack_vector.push_back(v);
 						++sscore[v];
 					}
 				}
@@ -424,7 +449,6 @@ namespace sat {
 					if (cur_solution[v] == constraint_term[c][j].sense) {
 						//score[v] += constraint_weight[c];
 						++m_var_info[v].m_score;
-							hack_vector.push_back(v);
 					}
 				}
 				break;
@@ -432,7 +456,6 @@ namespace sat {
 				break;
 			}
         }
-        }
 
         m_var_info[flipvar].m_score = -org_flipvar_score;
         sscore[flipvar] = -org_flipvar_sscore;
@@ -453,7 +476,6 @@ namespace sat {
         }
         // update all flipvar's neighbor's conf_change to true, add goodvar/okvar
 
-#if 0
         unsigned sz = var_neighbor[flipvar].size();
         for (unsigned i = 0; i < sz; ++i) {
             v = var_neighbor[flipvar][i];
@@ -463,18 +485,7 @@ namespace sat {
                 m_var_info[v].m_in_goodvar_stack = true;
             }
         }
-#else
+
-		unsigned sz = hack_vector.size();
-		for (unsigned i = 0; i < sz; ++i)
-		{
-			v = hack_vector[i];
-			m_var_info[v].m_conf_change = true;
-			if (score(v) > 0 && !already_in_goodvar_stack(v)) {
-				goodvar_stack.push_back(v);
-				m_var_info[v].m_in_goodvar_stack = true;
-			}
-		}
-#endif
     }
 
     bool local_search::tie_breaker_sat(bool_var v, bool_var best_var)  {
@@ -574,7 +585,7 @@ namespace sat {
     }
 
     void local_search::print_info() {
-        for (int v = 1; v <= num_vars(); ++v) {
+        for (unsigned v = 1; v <= num_vars(); ++v) {
             std::cout << var_neighbor[v].size() << '\t' << cur_solution[v] << '\t' << conf_change(v) << '\t' << score(v) << '\t' << sscore[v] << '\n';
         }
     }

src/sat/sat_local_search.h

@@ -64,7 +64,7 @@ namespace sat {
 
         // data structure for a term in constraint
         struct term {
-            int constraint_id;                   // constraint it belongs to
+            //int constraint_id;                   // constraint it belongs to
             int var_id;                          // variable id, begin with 1
             bool sense;                          // 1 for positive, 0 for negative
             //int coefficient;                   // all constraints are cardinality: coefficient=1
@@ -76,7 +76,9 @@ namespace sat {
         
         
         // terms arrays
-        svector<term>  var_term[MAX_VARS];         // var_term[i][j] means the j'th term of var i
+        //svector<term>  var_term[MAX_VARS];         // var_term[i][j] means the j'th term of var i
+		int_vector  pos_var_term[MAX_VARS];
+		int_vector  neg_var_term[MAX_VARS];
 		svector<term>  constraint_term[MAX_CONSTRAINTS];  // constraint_term[i][j] means the j'th term of constraint i
         unsigned m_num_vars, m_num_constraints;
 
@@ -136,7 +138,7 @@ namespace sat {
         
         // cutoff
         int      cutoff_time = 1;            // seconds
-        int      max_steps = 2000000000;     // < 2147483647
+        unsigned      max_steps = 2000000000;     // < 2147483647
         clock_t start, stop;
         double			best_time;
         

src/test/sat_local_search.cpp

@@ -80,6 +80,7 @@ void tst_sat_local_search(char ** argv, int argc, int& i) {
 
 	int v;
     while (i + 1 < argc) {
+        std::cout << argv[i + 1] << "\n";
         // set other ad hoc parameters.
         if (argv[i + 1][0] == '-' && i + 2 < argc) {
             switch (argv[i + 1][1]) {