title: Homework: binary tree - level-order trasversal
body: <p>is there a way to visit a binary tree from the lowest level to the higher (root) ?</p>
  
  <p>not from the root-level to the lowest!!!</p>
  
  <p>(and not using the level-order traversal and a stack...!!!) &lt;--- its opposite..</p>
  
  <p>so difficult...thank you!</p>