46 lines
831 B
Python
46 lines
831 B
Python
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class TreeNode:
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def __init__(self, val):
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self.val = val
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self.left = None
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self.right = None
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def isSymmetric(root):
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if not root:
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return True
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# no child nodes
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if not root.left and not root.right:
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return True
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# only left exists
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elif root.left and not root.right:
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return False
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# only right exists
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elif not root.left and root.right:
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return False
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# both exists
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if root.left.val == root.right.val:
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return True
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if root.left:
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leftRes = isSymmetric(root.left)
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if root.right:
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rightRes = isSymmetric(root.right)
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return leftRes and rightRes
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root = TreeNode(0)
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root.left = TreeNode(2)
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root.right = TreeNode(2)
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root.left.right = TreeNode(3)
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root.right.right = TreeNode(3)
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print(isSymmetric(root))
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