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Problem Statement

Given the root of a binary tree, invert the tree, and return its root.

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Examples

Example 1

Input:  root = [4, 2, 7, 1, 3, 6, 9]
Output: [4, 7, 2, 9, 6, 3, 1]

Example 2

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

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Constraints

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