Let us create binary tree shown in above diagram
Node root = newNode ( 1 ) ; root . left = newNode ( 2 ) ; root . right = newNode ( 3 ) ; root . left . left = newNode ( 4 ) ; root . left . right = newNode ( 5 ) ; root . left . right . left = newNode ( 6 ) ; System . out . println ( " Height ▁ of ▁ tree ▁ is ▁ " + heightOfTree ( root ) ) ; } }