update readme

lambdaplus · lambdaplus · commit 95d8b14bd6df · 2017-04-13T15:44:59.000+08:00
diff --git a/Algorithm/README.md b/Algorithm/README.md
@@ -3,3 +3,4 @@
 3. [删除链表中的重复元素](https://www.zybuluo.com/Scrazy/note/720542)
 4. [数组中的数组成最小值](https://www.zybuluo.com/Scrazy/note/720582)
 5. [索引为index 的丑数](https://www.zybuluo.com/Scrazy/note/720587)
+6. [反转链表](https://www.zybuluo.com/Scrazy/note/721436)
diff --git a/binary_tree.md b/binary_tree.md
@@ -328,3 +328,27 @@ class Solution:
             return True
         return is_same(pRoot.left, pRoot.right)
 ```
+### 二叉树镜像
+
+```
+# -*- coding:utf-8 -*-
+# class TreeNode:
+#     def __init__(self, x):
+#         self.val = x
+#         self.left = None
+#         self.right = None
+class Solution:
+    # 返回镜像树的根节点
+    def Mirror(self, root):
+        # write code here
+        if not root:
+            return None
+        elif not (root.left or root.right):
+            return root
+    	
+        root.left, root.right = root.right, root.left
+        if root.left:
+            self.Mirror(root.left)
+        if root.right:
+            self.Mirror(root.right)
+``` 
