Invert Binary Tree

01 · Question

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

02 · Solution

Reference solution

1def invertTree(root: Optional[TreeNode]) -> Optional[TreeNode]:
2    if not root:
3        return None
4    root.left, root.right = root.right, root.left
5    invertTree(root.left)
6    invertTree(root.right)
7    return root

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