From 8f91b8585fee97e025e70c0da729485c132d4ec8 Mon Sep 17 00:00:00 2001
From: ivan <ivan1016017@gmail.com>
Date: Mon, 13 Oct 2025 04:31:43 -0600
Subject: [PATCH] adding algo

---
 .../symmetric_tree.py                         | 32 +++++++++++++++++++
 .../test_symmetric_tree_round_20.py           | 15 +++++++++
 2 files changed, 47 insertions(+)
 create mode 100644 src/my_project/interviews/top_150_questions_round_20/symmetric_tree.py
 create mode 100644 tests/test_150_questions_round_20/test_symmetric_tree_round_20.py

diff --git a/src/my_project/interviews/top_150_questions_round_20/symmetric_tree.py b/src/my_project/interviews/top_150_questions_round_20/symmetric_tree.py
new file mode 100644
index 00000000..5343257d
--- /dev/null
+++ b/src/my_project/interviews/top_150_questions_round_20/symmetric_tree.py
@@ -0,0 +1,32 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+class Solution:
+
+    def isSymmetric(self, root: TreeNode) -> bool:
+        return self.check_mirror(root1=root, root2=root) 
+
+    def check_mirror(self, root1: TreeNode, root2: TreeNode):
+
+        if root1 is None and root2 is None: 
+            return True 
+        elif root1 is not None and root2 is not None:
+            try: 
+                root1.val 
+                root2.val
+            except:
+                return False 
+            
+            if root1.val != root2.val: 
+                return False 
+            else:
+                return self.check_mirror(root1.left, root2.right) \
+                       and self.check_mirror(root1.right, root2.left)   
+        else: 
+            return False 
diff --git a/tests/test_150_questions_round_20/test_symmetric_tree_round_20.py b/tests/test_150_questions_round_20/test_symmetric_tree_round_20.py
new file mode 100644
index 00000000..57a392da
--- /dev/null
+++ b/tests/test_150_questions_round_20/test_symmetric_tree_round_20.py
@@ -0,0 +1,15 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_20\
+.symmetric_tree import TreeNode, Solution
+
+class SymmetricTreeTestCase(unittest.TestCase):
+
+    def test_is_symmetric(self):
+        solution = Solution()
+        output = solution.isSymmetric(TreeNode(1, TreeNode(7), TreeNode(7)))
+        self.assertTrue(output)
+
+    def test_is_no_symmetric(self):
+        solution = Solution()
+        output = solution.isSymmetric(TreeNode(1, TreeNode(2), TreeNode(3)))
+        self.assertFalse(output)
\ No newline at end of file