Let us create binary tree shown in above diagram
Node root = newNode ( 7 ) ; root . left = newNode ( 6 ) ; root . right = newNode ( 5 ) ; root . left . left = newNode ( 4 ) ; root . left . right = newNode ( 3 ) ; root . right . left = newNode ( 2 ) ; root . right . right = newNode ( 1 ) ;