Counting nodes in a tree in Java

Question

First of all, I swear this is not homework, it\'s a question I was asked in an interview. I think I made a mess of it (though I did realise the solution requires recursion).

Answer 1

I like this better because it reads:

return count for left + count for rigth + 1

  int count() {
      return  countFor( getLeftChild() ) + countFor( getRightChild() ) + 1;
  }
  private int countFor( Tree tree )  { 
       return tree == null ? 0 : tree.count();
  }

A little more towards literate programming.

BTW, I don't like the getter/setter convention that is so commonly used on Java, I think a using leftChild() instead would be better:

  return countFor( leftChild() ) + countFor( rightChild() ) + 1;

Just like Hoshua Bloch explains here http://www.youtube.com/watch?v=aAb7hSCtvGw at min. 32:03

If you get it rigth your code reads...

BUT, I have to admit the get/set convention is now almost part of the language. :)

For many other parts, following this strategy creates self documenting code, which is something good.

Tony: I wonder, what was your answer in the interview.