All Downloads are FREE. Search and download functionalities are using the official Maven repository.

g0101_0200.s0145_binary_tree_postorder_traversal.readme.md Maven / Gradle / Ivy

145\. Binary Tree Postorder Traversal

Easy

Given the `root` of a binary tree, return _the postorder traversal of its nodes' values_.

**Example 1:**

![](https://assets.leetcode.com/uploads/2020/08/28/pre1.jpg)

**Input:** root = \[1,null,2,3\]

**Output:** \[3,2,1\] 

**Example 2:**

**Input:** root = \[\]

**Output:** \[\] 

**Example 3:**

**Input:** root = \[1\]

**Output:** \[1\] 

**Example 4:**

![](https://assets.leetcode.com/uploads/2020/08/28/pre3.jpg)

**Input:** root = \[1,2\]

**Output:** \[2,1\] 

**Example 5:**

![](https://assets.leetcode.com/uploads/2020/08/28/pre2.jpg)

**Input:** root = \[1,null,2\]

**Output:** \[2,1\] 

**Constraints:**

*   The number of the nodes in the tree is in the range `[0, 100]`.
*   `-100 <= Node.val <= 100`

**Follow up:** Recursive solution is trivial, could you do it iteratively?




© 2015 - 2025 Weber Informatics LLC | Privacy Policy