Coding SOlution of symmetric tree

Author: sushant097

coding_solutions/DataStructure_related/Tree/CheckSymmetryTree.py

@@ -0,0 +1,31 @@
+# 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 isSymmetric(self, root: Optional[TreeNode]) -> bool:
+        def isMirror(root1, root2):
+            # If both trees are empty, then they are mirror images
+            if root1 is None and root2 is None:
+                return True
+            
+            """ For two trees to be mirror images,
+                the following three conditions must be true
+                1 - Their root node's key must be same
+                2 - left subtree of left tree and right subtree
+                  of the right tree have to be mirror images
+                3 - right subtree of left tree and left subtree
+                   of right tree have to be mirror images
+            """
+            if (root1 is not None and root2 is not None):
+                if root1.val == root2.val:
+                    return (isMirror(root1.left, root2.right) and
+                            isMirror(root1.right, root2.left))
+            # If none of the above conditions is true then root1
+            # and root2 are not mirror images
+            return False
+        
+        return isMirror(root, root)
+