Populate Next Siblings Pointers in a Given Binary Tree OR Populate Next Right Pointers in Each Node

Objective: – Given a binary tree with three pointers left, right and nextSibling). Write the program to provide the nextsibling pointers.

This problem can also be referred as “Populating Next Right Pointers in Each Node”

Example:

Provide the Next Siblings Pointers in a Given Binary Tree.

Approach:

Use Recursion.
Start from the root, if root’s left node is not null then make it point to the root’s right child.
check if root’s nextsibling is not null, if NOT then make the next sibling of root’s right node point to the root’s nextsibling’s left child. (In our example node 5 points node 6, as per our statement, Parent of node 5 is Node 2, next sibling of node 2 is node 3, and left child of node 2 is node 6, So Node 5 will points to Node 6 )

Code:

Output:

1
2 3
4 5 6 7