Populating Next Right Pointers In Each Node II is an example of null problems. In this post we will see how we can solve in Javascript.

Problem Description

Follow up for problem Populating Next Right Pointers in Each Node. What if the given tree could be any binary tree? Would your previous solution still work?

Note: You may only use constant extra space.

For example, Given the following binary tree,

     1

   /  \

  2    3

 / \    \

4   5    7

After calling your function, the tree should look like:

     1 -> NULL

   /  \

  2 -> 3 -> NULL

 / \    \

4-> 5 -> 7 -> NULL

Solution: Please check the main.js snippet for the solution.  The idea is level order with two loops, outter loop If you have different approach in mind or have any suggestion for this implementation feel free to share in the comment below. Thanks!