145. Binary Tree Postorder Traversal

Practice Binary Tree Postorder Traversal for free on NudgeCode: Easy, Binary Tree pattern. Write it in Python or JavaScript, run the tests in your browser, and ask for a hint when you are stuck.

Return the values of a binary tree in postorder: the left subtree first, then the right subtree, and the node itself last.

Example

root = [1,null,2,3]  ->  [3,2,1]

Constraints

• 0 <= number of nodes <= 100
• -100 <= Node.val <= 100