Problem Statement

Given the root of a binary tree, return the inorder traversal of its nodes' values.

Inorder traversal visits nodes in the order: Left subtree, Root node, Right subtree.

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Examples

Example 1

Input: root = [1,null,2,3]
Output: [1,3,2]

Example 2

Input: root = []
Output: []

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Constraints

• The number of nodes in the tree is in the range [0, 100].
• -100 ≤ Node.val ≤ 100