aloalgoBinary Tree Postorder Traversal
Easy
You are given the root of a binary tree.
Your task is to return the postorder traversal of the values of its nodes.
Note that:
- In a postorder traversal, you should first visit the left subtree, then the right subtree, and finally the
rootnode itself.
Return a list of integers representing the node values in postorder.
Example 1
Input
Output
[3, 2, 1]
Explanation:
The postorder traversal is Left -> Right -> Root. For the given tree, the left subtree is null, the right subtree is node 2 (which has a left child 3), so we visit 3, then 2, then the root 1.
Example 2
Input
None
Output
[]
Explanation:
An empty tree has no nodes, so the traversal is an empty list.
Example 3
Input
Output
[1, 3, 2, 6, 9, 7, 4]
Explanation:
Following Left -> Right -> Root traversal order results in the sequence [1, 3, 2, 6, 9, 7, 4].
Input
Output
[3, 2, 1]