title: Lowest Common Ancestor of a Binary Tree
body: <p>This is a popular interview question and the only article I can find on the topic is one from <a href="http://www.topcoder.com/tc?module=Static&amp;d1=tutorials&amp;d2=lowestCommonAncestor">TopCoder</a>. Unfortunately for me, it looks overly complicated from an interview answer's perspective.</p>
  
  <p>Isn't there a simpler way of doing this other than plotting the path to both nodes and deducing the ancestor? (This is a popular answer, but there's a variation of the interview question asking for a constant space answer).</p>