balanced_binary_tree.py (807B)
| # 110. Balanced Binary Tree
import leetcode
"""
given a binary tree, determine if it is height balanced
"""
class Solution(object):
def isBalanced(self, root):
"""
:type root: Optional[TreeNode]
:rtype: bool
"""
self.balanced = True
def dfs(node):
if not node:
return 0
l, r = dfs(node.left), dfs(node.right)
if abs(l - r) > 1:
self.balanced = False
return max(l, r) + 1
dfs(root)
return self.balanced
if __name__ == "__main__":
obj = Solution()
r1 = leetcode.treenode_build(vals=[3, 9, 20, None, None, 15, 7])
r2 = leetcode.treenode_build(vals=[1, 2, 2, 3, 3, None, None, 4, 4])
print(obj.isBalanced(r1))
print(obj.isBalanced(r2))
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