https://leetcode.com/problems/reverse-odd-levels-of-binary-tree

medium/reverse_odd_levels_of_binray_tree.py

@@ -0,0 +1,23 @@
+# https://leetcode.com/problems/reverse-odd-levels-of-binary-tree
+from typing import Optional
+
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+class Solution:
+    def reverseOddLevels(self, root: Optional[TreeNode]) -> Optional[TreeNode]:
+        def traverse(left: Optional[TreeNode], right: Optional[TreeNode], depth: int):
+            if left is None or right is None:
+                return
+            if depth % 2 == 1:
+                tmp = left.val
+                left.val = right.val
+                right.val = tmp
+            traverse(left.left, right.right, depth + 1)
+            traverse(left.right, right.left, depth + 1)
+        if root is not None:
+            traverse(root.left, root.right, 1)
+        return root
+