create Tree
Node * root = newNode ( 27 ) ; root -> left = newNode ( 9 ) ; root -> right = newNode ( 81 ) ; root -> left -> left = newNode ( 3 ) ; root -> left -> right = newNode ( 10 ) ; root -> right -> left = newNode ( 70 ) ; root -> right -> right = newNode ( 243 ) ; root -> right -> right -> left = newNode ( 81 ) ; root -> right -> right -> right = newNode ( 909 ) ;