title: What does it mean for two binary trees to be isomorphic?
body: <p>What does it mean for two binary trees to be isomorphic?  I've been looking online and I can't seem to find a clear explanation.</p>
  
  <p>As far as I understand, two trees are isomorphic if they have the same shape. So I'm guessing two identical trees which can contain different values in the nodes.</p>