42 lines
1017 B
Python
42 lines
1017 B
Python
from typing import Optional
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class TreeNode:
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"""A class representing a binary tree node."""
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def __init__(self, val: int = 0, left: Optional['TreeNode'] = None, right: Optional['TreeNode'] = None):
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"""
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Initializes a new instance of the TreeNode class.
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Args:
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val: The value of the node.
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left: The left child of the node.
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right: The right child of the node.
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"""
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self.val = val
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self.left = left
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self.right = right
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def invert_tree(root: Optional[TreeNode]) -> Optional[TreeNode]:
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"""
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Inverts a binary tree.
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Args:
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root: The root node of the binary tree.
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Returns:
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The root node of the inverted binary tree.
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"""
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if root is None:
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return None
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# Swap left and right children of the root node
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root.left, root.right = root.right, root.left
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# Recursively invert the left and right subtrees
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invert_tree(root.left)
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invert_tree(root.right)
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return root
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