perf: apply loop unswitching and variable hoisting in Minimizer

src/main/java/org/eu/autogex/algorithms/Minimizer.java

@@ -128,20 +128,25 @@ private static Map<BehaviorSignature, Set<State>> splitGroup(
         // Maps the behavioral "signature" of a state to the subgroup of states sharing it
         Map<BehaviorSignature, Set<State>> subGroups = new HashMap<>();
 
+        // Optimization: Hoist map lookup and array length out of the loop
+        Map<State, Map<Character, State>> transitionTable = dfa.getTransitionTable();
+        int alphabetLen = alphabetArray.length;
+
         for (State s : group) {
             // The signature is: "For each character, which partition do I end up in?"
-            int[] targets = new int[alphabetArray.length];
-            Map<Character, State> transitions = dfa.getTransitionTable().get(s);
+            int[] targets = new int[alphabetLen];
+            Map<Character, State> transitions = transitionTable.get(s);
 
-            for (int i = 0; i < alphabetArray.length; i++) {
-                if (transitions == null) {
-                    targets[i] = -1;
-                    continue;
+            // Optimization: Unswitch condition for trap states and use fast array fill
+            if (transitions == null) {
+                Arrays.fill(targets, -1);
+            } else {
+                for (int i = 0; i < alphabetLen; i++) {
+                    State destination = transitions.get(alphabetArray[i]);
+                    Integer targetPartitionId =
+                            destination != null ? stateToPartitionId.get(destination) : null;
+                    targets[i] = targetPartitionId != null ? targetPartitionId : -1;
                 }
-                State destination = transitions.get(alphabetArray[i]);
-                Integer targetPartitionId =
-                        destination != null ? stateToPartitionId.get(destination) : null;
-                targets[i] = targetPartitionId != null ? targetPartitionId : -1;
             }
             BehaviorSignature behaviorSignature = new BehaviorSignature(targets);