Solved invert binary tree problem

invert_binary_tree.py

@@ -0,0 +1,23 @@
+# Definition for a binary tree node.
+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 invert_tree(self, root: Optional[TreeNode]) -> Optional[TreeNode]:
+        if not root: 
+            return None
+
+        temp = root.left
+        root.left = root.right
+        root.right = temp
+
+        self.invert_tree(root.left)
+        self.invert_tree(root.right)
+
+        return root