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226. Invert Binary Tree

We invert a binary tree. Pretty straightforward, just recursively swap the nodes.

The solution is as follows:

class Solution:
    def invertTree(self, root: Optional[TreeNode]) -> Optional[TreeNode]:
        if not root:
            return root
        root.left, root.right = self.invertTree(root.right), self.invertTree(root.left)
        return root

_ Time Complexity:

O(n) - Where n is the number of nodes in the tree.

_ Space Complexity:

O(h) - Where h is the height of the tree.