Refactory day 16 puzzle

src/main/java/com/adventofcode/flashk/day16/EmptyTile.java

@@ -6,13 +6,8 @@
 
 public class EmptyTile extends Tile {
 
-    private static final char EMPTY = '.';
-
-    protected EmptyTile(char value, int row, int col) {
-        super(value, row, col);
-        if(value != EMPTY) {
-            throw new IllegalArgumentException("Value is not an empty tile: '.'");
-        }
+    protected EmptyTile(int row, int col) {
+        super(row, col);
     }
 
     @Override

src/main/java/com/adventofcode/flashk/day16/MirrorLeftTile.java

@@ -0,0 +1,28 @@
+package com.adventofcode.flashk.day16;
+
+import com.adventofcode.flashk.common.Vector2;
+
+import java.util.List;
+
+public class MirrorLeftTile extends Tile {
+
+    public MirrorLeftTile(int row, int col) {
+        super(row, col);
+    }
+
+    @Override
+    public List<Vector2> nextDirections(Vector2 direction) {
+
+        Vector2 newDirection = new Vector2(direction);
+
+        if(RIGHT_DIRECTION.equals(direction) || LEFT_DIRECTION.equals(direction)) {
+            newDirection.rotateLeft();
+        } else {
+            newDirection.rotateRight();
+        }
+
+        return List.of(newDirection);
+
+    }
+
+}

src/main/java/com/adventofcode/flashk/day16/MirrorRightTile.java

@@ -0,0 +1,27 @@
+package com.adventofcode.flashk.day16;
+
+import com.adventofcode.flashk.common.Vector2;
+
+import java.util.List;
+
+public class MirrorRightTile extends Tile {
+
+    public MirrorRightTile(int row, int col) {
+        super(row, col);
+    }
+
+    @Override
+    public List<Vector2> nextDirections(Vector2 direction) {
+
+        Vector2 newDirection = new Vector2(direction);
+
+        if(RIGHT_DIRECTION.equals(direction) || LEFT_DIRECTION.equals(direction)) {
+            newDirection.rotateRight();
+        } else {
+            newDirection.rotateLeft();
+        }
+
+        return List.of(newDirection);
+    }
+
+}

src/main/java/com/adventofcode/flashk/day16/SplitterHorizontalTile.java

@@ -0,0 +1,23 @@
+package com.adventofcode.flashk.day16;
+
+import com.adventofcode.flashk.common.Vector2;
+
+import java.util.List;
+
+public class SplitterHorizontalTile extends Tile{
+
+    public SplitterHorizontalTile(int row, int col) {
+        super(row, col);
+    }
+
+    @Override
+    public List<Vector2> nextDirections(Vector2 direction) {
+
+        if(RIGHT_DIRECTION.equals(direction) || LEFT_DIRECTION.equals(direction)) {
+            return List.of(direction);
+        }
+
+        return List.of(Vector2.left(), Vector2.right());
+
+    }
+}

src/main/java/com/adventofcode/flashk/day16/SplitterVerticalTile.java

@@ -0,0 +1,22 @@
+package com.adventofcode.flashk.day16;
+
+import com.adventofcode.flashk.common.Vector2;
+
+import java.util.List;
+
+public class SplitterVerticalTile extends Tile {
+
+    public SplitterVerticalTile(int row, int col) {
+        super(row, col);
+    }
+
+    @Override
+    public List<Vector2> nextDirections(Vector2 direction) {
+
+        if(UP_DIRECTION.equals(direction) || DOWN_DIRECTION.equals(direction)) {
+            return List.of(direction);
+        }
+
+        return List.of(Vector2.up(), Vector2.down());
+    }
+}

src/main/java/com/adventofcode/flashk/day16/TheFloorWillBeLava.java

@@ -31,12 +31,13 @@ public long solveA(){
 
 
     private long bfs(Vector2 startPosition, Vector2 startingDirection) {
-    // Start conditions
-        Tile startingTile = map[startPosition.getY()][startPosition.getX()];
 
         Queue<Tile> tilesQueue = new LinkedList<>();
         Queue<Vector2> directionsQueue = new LinkedList<>();
+
+        Tile startingTile = map[startPosition.getY()][startPosition.getX()];
         startingTile.visit(startingDirection);
+
         tilesQueue.add(startingTile);
         directionsQueue.add(startingDirection);
 
@@ -107,14 +108,15 @@ private Optional<Tile> nextTile(Vector2 nextDirection, Tile currentTile) {
         Vector2 currentTilePos = new Vector2(currentTile.getCol(), currentTile.getRow());
         Vector2 nextPosition = Vector2.transform(nextDirection, currentTilePos);
 
+        // Exclude out of bounds tiles
         if(nextPosition.getX() >= 0 &&
                 nextPosition.getX() < cols &&
                 nextPosition.getY() >= 0 &&
                 nextPosition.getY() < rows) {
 
             Tile nextTile = map[nextPosition.getY()][nextPosition.getX()];
 
-            // Next tile must NOT have been visited from that direction
+            // Exclude tiles that have been already visited from that direction
             if(!nextTile.isVisited(nextDirection)) {
                 return Optional.of(nextTile);
             }
@@ -139,11 +141,11 @@ private long countVisitedTiles() {
     private Tile buildTile(char value, int row, int col) {
 
         return switch (value) {
-            case '.': yield new EmptyTile(value, row, col);
-            case '\\': yield new MirrorTileLeft(value, row, col);
-            case '/': yield new MirrorTileRight(value, row, col);
-            case '|': yield new SplitterTileVertical(value, row, col);
-            case '-': yield new SplitterTileHorizontal(value, row, col);
+            case '.': yield new EmptyTile(row, col);
+            case '\\': yield new MirrorLeftTile(row, col);
+            case '/': yield new MirrorRightTile(row, col);
+            case '|': yield new SplitterVerticalTile(row, col);
+            case '-': yield new SplitterHorizontalTile(row, col);
             default: throw new IllegalArgumentException("Unexpected value: "+value);
         };
     }

src/main/java/com/adventofcode/flashk/day16/Tile.java

@@ -7,7 +7,7 @@
 import java.util.List;
 import java.util.Set;
 
-@Getter
+ @Getter
 public abstract class Tile {
 
     // Possible directions in tiles
@@ -16,13 +16,11 @@ public abstract class Tile {
     public static final Vector2 UP_DIRECTION = Vector2.down();
     public static final Vector2 DOWN_DIRECTION = Vector2.up();
 
-    private final char value;
     private final int row;
     private final int col;
     private final Set<Vector2> visitedDirections = new HashSet<>();
 
-    protected Tile(char value, int row, int col) {
-        this.value = value;
+    protected Tile(int row, int col) {
         this.row = row;
         this.col = col;
     }

src/test/java/com/adventofcode/flashk/day16/MirrorTileTest.java

@@ -9,8 +9,8 @@
 
 class MirrorTileTest {
 
-    private MirrorTile left = new MirrorTileLeft('\\',1,1);
-    private MirrorTile right = new MirrorTileRight('/',1,1);
+    private final Tile left = new MirrorLeftTile(1,1);
+    private final Tile right = new MirrorRightTile(1,1);
 
     @Test
     void reflectLeftMirrorWithRightDirection() {

src/test/java/com/adventofcode/flashk/day16/SplitterTileTest.java

@@ -9,8 +9,8 @@
 
 class SplitterTileTest {
 
-    private SplitterTile vertical = new SplitterTileVertical('|',1,1);
-    private SplitterTile horizontal = new SplitterTileHorizontal('-',1,1);
+    private final Tile vertical = new SplitterVerticalTile(1,1);
+    private final Tile horizontal = new SplitterHorizontalTile(1,1);
 
     @Test
     void nextDirectionsSplitterTileVerticalLeft() {