From 2cfdf9209ffce2a57b97216bfa330389681dae9d Mon Sep 17 00:00:00 2001
From: mike <michael@appmodel.nl>
Date: Sat, 10 Jan 2026 05:43:17 +0100
Subject: [PATCH] introduce bitloops

---
 pom.xml                                    |  4 ++--
 src/main/java/puzzle/SwedishGenerator.java | 25 +++++++++++++++-------
 src/test/java/puzzle/MainTest.java         |  6 +++---
 3 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/pom.xml b/pom.xml
index 524f540..bb3f140 100644
--- a/pom.xml
+++ b/pom.xml
@@ -64,7 +64,7 @@
         <dependency>
             <groupId>mike.processor</groupId>
             <artifactId>puzzle-processor</artifactId>
-            <version>1.2-SNAPSHOT</version>
+            <version>1.4-SNAPSHOT</version>
             <scope>provided</scope>
         </dependency>
     </dependencies>
@@ -104,7 +104,7 @@
                         <path>
                             <groupId>mike.processor</groupId>
                             <artifactId>puzzle-processor</artifactId>
-                            <version>1.2-SNAPSHOT</version>
+                            <version>1.4-SNAPSHOT</version>
                         </path>
                     </annotationProcessorPaths>
                     <source>25</source>
diff --git a/src/main/java/puzzle/SwedishGenerator.java b/src/main/java/puzzle/SwedishGenerator.java
index 06cbf8c..9c07ddb 100644
--- a/src/main/java/puzzle/SwedishGenerator.java
+++ b/src/main/java/puzzle/SwedishGenerator.java
@@ -62,10 +62,11 @@ public record SwedishGenerator(Rng rng) {
    record Pick(Slot slot, CandidateInfo info, boolean done) { }
    
    // Directions for '1'..'6'
-   static final nbrs_16[] OFFSETS = Neighbors9x8.OFFSETS;
-   static final nbrs_8[]  nbrs8   = Neighbors9x8.nbrs8;
-   static final nbrs_8[]  nbrs4   = Neighbors9x8.nbrs4;
-   static final rci[]     IT      = Neighbors9x8.IT;
+   static final nbrs_16[] OFFSETS       = Neighbors9x8.OFFSETS;
+   static final nbrs_8[]  nbrs8         = Neighbors9x8.nbrs8;
+   static final nbrs_8[]  nbrs4         = Neighbors9x8.nbrs4;
+   static final rci[]     IT            = Neighbors9x8.IT;
+   static final long[]    INBR8_PACKEDT = Neighbors9x8.NBR8_PACKED;
    
    static final Pick PICK_DONE     = new Pick(null, null, true);
    static final Pick PICK_NOT_DONE = new Pick(null, null, false);
@@ -388,7 +389,7 @@ public record SwedishGenerator(Rng rng) {
       final long[] penalty = { 0 };
       
       var clueCount = grid.clueCount();
-      penalty[0] += 8L * Math.abs(clueCount - TARGET_CLUES);
+      penalty[0] += ((long) Math.abs(clueCount - TARGET_CLUES)) << 3;
       
       var ctx  = CTX.get();
       var covH = ctx.covH;
@@ -451,8 +452,16 @@ public record SwedishGenerator(Rng rng) {
             var p  = stack[--sp];
             int rr = Grid.c(p), cc = Grid.r(p);
             size++;
-            
-            for (var d : nbrs8) {
+            long packed = Neighbors9x8.NBR8_PACKED[Grid.offset(rr, cc)];
+            int  n      = (int) (packed >>> 56);
+            for (int k = 0; k < n; k++) {
+               int nidx = (int)((packed >>> (k * 7)) & 0x7F);
+               
+               if (seen.get(nidx) || grid.isLetterAt(nidx)) continue;
+               seen.set(nidx);
+               stack[sp++] = nidx;
+            }
+           /* for (var d : nbrs8) {
                var nr = rr + d.r();
                var nc = cc + d.c();
                if (nr < 0 || nr >= R || nc < 0 || nc >= C) continue;
@@ -460,7 +469,7 @@ public record SwedishGenerator(Rng rng) {
                if (seen.get(nidx) || grid.isLetterAt(nidx)) continue;
                seen.set(nidx);
                stack[sp++] = nidx;
-            }
+            } */
          }
          
          if (size >= 2) penalty[0] += (size - 1L) * 120L;
diff --git a/src/test/java/puzzle/MainTest.java b/src/test/java/puzzle/MainTest.java
index 0e87744..0c8aadd 100644
--- a/src/test/java/puzzle/MainTest.java
+++ b/src/test/java/puzzle/MainTest.java
@@ -166,9 +166,9 @@ public class MainTest {
       
       // Regression baseline for seed search starting at 12347, pop 4, gens 20
       Assertions.assertEquals(12347, foundSeed, "Found seed changed");
-      Assertions.assertEquals(20, res.filled().clueMap().size(), "Number of assigned words changed");
-      Assertions.assertEquals(758.55, res.filled().stats().simplicity, 1e-9, "Simplicity value changed");
-      Assertions.assertArrayEquals(new byte[]{ 'M', 'A', 'N', 'T', 'A' }, res.filled().clueMap().get(849).word());
+      Assertions.assertEquals(24, res.filled().clueMap().size(), "Number of assigned words changed");
+      Assertions.assertEquals(735.7083333333334, res.filled().stats().simplicity, 1e-9, "Simplicity value changed");
+      Assertions.assertArrayEquals(new byte[]{ 'E', 'B', 'B', 'E', 'N' }, res.filled().clueMap().get(515).word());
    }
    @Test
    public void testIsLetterA() {