create 0236-lowest-common-ancestor-of-a-binary-tree.py

Author: abe-101

python/0236-lowest-common-ancestor-of-a-binary-tree.py

@@ -0,0 +1,26 @@
+# Definition for a binary tree node.
+# class TreeNode:
+#     def __init__(self, x):
+#         self.val = x
+#         self.left = None
+#         self.right = None
+
+class Solution:
+    def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode':
+        if not root:
+            return
+        if root == p or root == q:
+            return root
+
+        left = self.lowestCommonAncestor(root.left, p, q)
+        right = self.lowestCommonAncestor(root.right, p, q)
+
+        if left and right:
+            return root
+
+        if left:
+            return left
+        if right:
+            return right
+
+        return None