Adding missing example.

Author: Clément

source/code/projects/AVLTree/AVLTree/AVLTree.cs

@@ -53,7 +53,53 @@ private int GetHeight(Node nodeP)
         else
             return nodeP.Height;
     }
-    
+    // We have a method to update the height
+    // of a node, and of its sub-trees.
+    private int UpdateHeight(Node nodeP)
+    {
+        int height = -1;
+        if (nodeP != null)
+        {
+            int nodeLeft = UpdateHeight(nodeP.left);
+            int nodeRight = UpdateHeight(nodeP.right);
+            height = Math.Max(nodeLeft, nodeRight) + 1;
+            nodeP.Height = height;
+        }
+        return height;
+    }
+
+    // 
+    private int SubtreeBalance(Node nodeP)
+    {
+        // Will return
+        // a negative number if subtree is right-heavy
+        // a positive number if subtree is left-heavy
+        // 0 if the subtree is perfectly balanced.
+        UpdateHeight(nodeP.left);
+        UpdateHeight(nodeP.right);
+        int balance;
+        if (nodeP == null)
+        {
+            balance = 0;
+        }
+        else if (nodeP.left == null && nodeP.right == null)
+        {
+            balance = 0;
+        }
+        else if (nodeP.left == null)
+        {
+            balance = -(nodeP.right.Height + 1);    // right side heavy represented by negative number
+        }
+        else if (nodeP.right == null)
+        {
+            balance = nodeP.left.Height + 1;
+        }
+        else
+        {
+            balance =  nodeP.left.Height - nodeP.right.Height;
+        }
+        return balance;
+    }
     public void Insert(T valueP)
     {
         root = Insert(valueP, root);

source/diag/gra/bstree_example_7.txt

@@ -0,0 +1,17 @@
+%%% A balanced binary search tree containing 1, 2, …, 1000.
+
+A((64))-->B((32))
+A-->C((80))
+B-->D((16))
+B-->E((48))
+C-->F((72))
+C-->G((88))
+F-.->H1:::hidden
+F-.->H2:::hidden
+G-.->H3:::hidden
+G-.->H4:::hidden
+D-.->H5:::hidden
+D-.->H6:::hidden
+E-.->H7:::hidden
+E-.->H8:::hidden
+