* Done with "538. Convert BST to Greater Tree".

garciparedes · garciparedes · commit 35cd3b460d08 · 2022-04-16T19:09:34.000+02:00
diff --git a/problems/0538_convert_bst_to_greater_tree.py b/problems/0538_convert_bst_to_greater_tree.py
@@ -0,0 +1,23 @@
+# Definition for a binary tree node.
+# class TreeNode:
+#     def __init__(self, val=0, left=None, right=None):
+#         self.val = val
+#         self.left = left
+#         self.right = right
+class Solution:
+    def convertBST(self, root: Optional[TreeNode]) -> Optional[TreeNode]:
+        self._traverse(root, 0)
+        return root
+    
+    def _traverse(self, root: Optional[TreeNode], cum: int) -> int:
+        if root is None:
+            return cum
+        
+        cum = self._traverse(root.right, cum)
+        
+        cum += root.val
+        root.val = cum
+        
+        cum = self._traverse(root.left, cum)
+        
+        return cum
