Given a sorted (increasing order) array, write an algorithm to create a binary tree with minimal height.

Algorithm:
1.     Insert into the tree the middle element of the array.
2.     Insert (into the left subtree) the left subarray elements
3.     Insert (into the right subtree) the right subarray elements
4.     Recurse


1      public static TreeNode addToTree(int arr[], int start, int end){
2              if (end < start) {
3                       return null;
4              }
5              int mid = (start + end) / 2;
6              TreeNode n = new TreeNode(arr[mid]);
7              n.left = addToTree(arr, start, mid - 1);
8              n.right = addToTree(arr, mid + 1, end);
9              return n;
10     }
11        
12     public static TreeNode createMinimalBST(int array[]) {
13             return addToTree(array, 0, array.length - 1);
14     }