Prerequisites : Binary Trees.
Problem: Print nodes of a given binary tree in a postorder manner.
Solution Approach: Postorder traversal is another depthfirst traversal method for binary trees. In postorder traversal, the nodes are visited in the following sequence:

 Traverse the Left Subtree:
 Recursively perform a postorder traversal on the left subtree of the current node.
 For each node in the left subtree, repeat step 1.
 Traverse the Left Subtree:

 Traverse the Right Subtree:
 Recursively perform a postorder traversal on the right subtree of the current node.
 For each node in the right subtree, repeat step 1.
 Traverse the Right Subtree:

 Visit the Root Node:
 Process/visit the data (or perform an operation) associated with the root node.
 Visit the Root Node:
Time complexity: O(N), where N is the number of nodes in the tree. Each node is visited once.
Space complexity: O(1), as we donâ€™t need any extra space.