Reduced Floor Doorways

Added code to minimize the number of doorways that involve dropping
through the floor. Added a DisjointSet class as part of the
implementation. I also split the maze construction process into two
classes (MazeDesigner and MazeBuilder) to make it clearer.

src/main/java/StevenDimDoors/experimental/MazeDesign.java

@@ -0,0 +1,48 @@
+package StevenDimDoors.experimental;
+
+import java.util.ArrayList;
+
+public class MazeDesign
+{
+	private PartitionNode root;
+	private DirectedGraph<PartitionNode, DoorwayData> rooms;
+	private ArrayList<IGraphNode<PartitionNode, DoorwayData>> cores;
+	
+	public MazeDesign(PartitionNode root, DirectedGraph<PartitionNode, DoorwayData> rooms,
+			ArrayList<IGraphNode<PartitionNode, DoorwayData>> cores)
+	{
+		this.root = root;
+		this.rooms = rooms;
+		this.cores = cores;
+	}
+
+	public PartitionNode getRootPartition()
+	{
+		return root;
+	}
+
+	public DirectedGraph<PartitionNode, DoorwayData> getRoomGraph()
+	{
+		return rooms;
+	}
+
+	public ArrayList<IGraphNode<PartitionNode, DoorwayData>> getCoreNodes()
+	{
+		return cores;
+	}
+	
+	public int width()
+	{
+		return root.width();
+	}
+	
+	public int height()
+	{
+		return root.height();
+	}
+	
+	public int length()
+	{
+		return root.length();
+	}
+}