added 101. Symmetric Tree

0ff5ec · 0ff5ec · commit 4ed3c71656be · 2019-12-14T13:31:51.000-08:00
diff --git a/isSymmetric.py b/isSymmetric.py
@@ -0,0 +1,22 @@
+# Definition for a binary tree node.
+# class TreeNode(object):
+#     def __init__(self, x):
+#         self.val = x
+#         self.left = None
+#         self.right = None
+
+class Solution(object):
+    def isSymmetric(self, root):
+        """
+        :type root: TreeNode
+        :rtype: bool
+        """
+        if root == None:
+            return True
+        return self.isMirror(root.left, root.right)
+    def isMirror(self, tree1, tree2):
+        if tree1 == None or tree2 == None:
+            return tree1 == tree2
+        if tree1.val != tree2.val:
+            return False
+        return self.isMirror(tree1.left, tree2.right) and self.isMirror(tree1.right, tree2.left)
