(Recursively)_Symmetric_Tree

CodingProgrammer · CodingProgrammer · commit 60c3cbba349e · 2017-12-22T09:18:30.000+08:00
diff --git a/101(Recursively)_Symmetric_Tree.py b/101(Recursively)_Symmetric_Tree.py
@@ -0,0 +1,30 @@
+# 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 is None:
+            return True
+        else:
+            return self.isMirror(root.left, root.right)
+    
+    def isMirror(self, left, right):
+        if None == left and None == right:
+            return True
+        elif None ==left or None == right:
+            return False
+        elif left.val == right.val:
+            outPair = self.isMirror(left.left, right.right)
+            inPair = self.isMirror(left.right, right.left)
+            return outPair and inPair
+        else:
+            return False
