Sounds like he knows how to invert binary trees [1]. So the rest will come later...<p>[1] - <a href="https:&#x2F;&#x2F;twitter.com&#x2F;mxcl&#x2F;status&#x2F;608682016205344768?lang=en" rel="nofollow">https:&#x2F;&#x2F;twitter.com&#x2F;mxcl&#x2F;status&#x2F;608682016205344768?lang=en</a>