Driver program to test above
public static void main ( String args [ ] ) { ExpressionTree et = new ExpressionTree ( ) ; String postfix = " ab + ef * g * - " ; char [ ] charArray = postfix . toCharArray ( ) ; Node root = et . constructTree ( charArray ) ; System . out . println ( " infix ▁ expression ▁ is " ) ; et . inorder ( root ) ; } }