Objective: - Given a binary tree, print it in vertical order path.
What is Vertical Order
as you can see in the example above, ,, [1,5,6],, are the verical order of the given binary tree.
- Its a tricky solution.
- Do the inorder traversal.
- Take a variable called level, when ever you go left, do level++ AND when ever you go right do level–.
- With step above we have separated out the levels vertically.
- Now you need to store the elements of each level, so create a TreeMap and the (key,value) pair will be (level,elements at that level).
- At the end iterate through the TreeMap and print the results.
  [5, 1, 6]