Print Binary Tree levels in sorted order

Given a Binary tree, the task is to print its all level in sorted order

Examples:

Input :     7
         /    \
       6       5
      / \     / \
     4  3    2   1
Output : 
7
5 6
1 2 3 4

Here we can use two Priority queue for print in sorted order. We create an empty queue q and two priority queues, current_level and next_level. We use NULL as a separator between two levels. Whenever we encounter NULL in normal level order traversal, we swap current_level and next_level.

Print Binary Tree levels in sorted order : https://www.geeksforgeeks.org/print-binary-tree-levels-sorted-order/