1 files changed, 9 insertions, 5 deletions

diff --git a/subprojects/store/src/main/java/tools/refinery/store/statecoding/neighbourhood/NeighbourhoodCalculator.java b/subprojects/store/src/main/java/tools/refinery/store/statecoding/neighbourhood/NeighbourhoodCalculator.java
index 785fda7a..1442c915 100644
--- a/subprojects/store/src/main/java/tools/refinery/store/statecoding/neighbourhood/NeighbourhoodCalculator.java
+++ b/subprojects/store/src/main/java/tools/refinery/store/statecoding/neighbourhood/NeighbourhoodCalculator.java
@@ -18,21 +18,25 @@ import java.util.List;
 import java.util.Objects;
 
 public class NeighbourhoodCalculator extends AbstractNeighbourhoodCalculator implements StateCodeCalculator {
+        private ObjectCodeImpl previousObjectCode = new ObjectCodeImpl();
+        private ObjectCodeImpl nextObjectCode = new ObjectCodeImpl();
+
         public NeighbourhoodCalculator(List<? extends Interpretation<?>> interpretations, IntSet individuals) {
                 super(interpretations, individuals);
         }
 
         public StateCoderResult calculateCodes() {
-                ObjectCodeImpl previousObjectCode = new ObjectCodeImpl();
+                previousObjectCode.clear();
+                nextObjectCode.clear();
                 initializeWithIndividuals(previousObjectCode);
 
                 int rounds = 0;
                 do {
-                        final ObjectCodeImpl nextObjectCode = rounds == 0 ? new ObjectCodeImpl() :
-                                        new ObjectCodeImpl(previousObjectCode.getSize());
-
                         constructNextObjectCodes(previousObjectCode, nextObjectCode);
+                        var tempObjectCode = previousObjectCode;
                         previousObjectCode = nextObjectCode;
+                        nextObjectCode = tempObjectCode;
+                        nextObjectCode.clear();
                         rounds++;
                 } while (rounds <= 7 && rounds <= previousObjectCode.getEffectiveSize());
 
@@ -43,7 +47,7 @@ public class NeighbourhoodCalculator extends AbstractNeighbourhoodCalculator imp
         private long calculateLastSum(ObjectCode codes) {
                 long result = 0;
                 for (var nullImpactValue : nullImpactValues) {
-                        result = result * 31 + Objects.hashCode(((Interpretation<?>) nullImpactValue).get(Tuple0.INSTANCE));
+                        result = result * PRIME + Objects.hashCode(((Interpretation<?>) nullImpactValue).get(Tuple0.INSTANCE));
                 }
 
                 for (int i = 0; i < codes.getSize(); i++) {