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Diffstat (limited to 'balanced_binary_tree.py')
-rw-r--r-- | balanced_binary_tree.py | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/balanced_binary_tree.py b/balanced_binary_tree.py new file mode 100644 index 0000000..a677b56 --- /dev/null +++ b/balanced_binary_tree.py @@ -0,0 +1,34 @@ +# 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)) |