ADD: best rank on both leaf and internal nodes

src/mhtree/ObjectToNodeDistanceRank.java

@@ -3,26 +3,37 @@ package mhtree;
 import messif.objects.LocalAbstractObject;
 
 import static mhtree.ObjectToNodeDistance.NEAREST;
+import static mhtree.ObjectToNodeDistance.FURTHEST;
 
 /**
- * Represents the rank of a node in the priority queue in a query operation.
+ * Represents the rank of a node in the priority queue
  */
 public class ObjectToNodeDistanceRank implements Comparable<ObjectToNodeDistanceRank> {
 
     private final Node node;
     private final double distance;
 
-    public ObjectToNodeDistanceRank(LocalAbstractObject object, Node node) {
+    public ObjectToNodeDistanceRank(LocalAbstractObject object, Node node, int k) {
         this.node = node;
 
         if (node.isLeaf()) {
             this.distance = NEAREST.getDistance(object, node);
-        } else {
+            return;
+        }
+
+        if (k == 1) {
             if (node.isCovered(object)) {
-                this.distance = -node.getDistance(object);
+                this.distance = -FURTHEST.getDistance(object, node);
             } else {
-                this.distance = node.getDistance(object);
+                this.distance = FURTHEST.getDistance(object, node);
             }
+            return;
+        }
+
+        if (node.isCovered(object)) {
+            this.distance = -NEAREST.getDistance(object, node);
+        } else {
+            this.distance = NEAREST.getDistance(object, node);
         }
     }