Merge pull request taizilongxu#91 from oillamp/master

style: code style

Author: taizilongxu

Readme.md

@@ -1790,9 +1790,9 @@ def maxDepth(root):
 def isSameTree(p, q):
     if p == None and q == None:
         return True
-    elif p and q :
+    elif p and q:
         return p.val == q.val and isSameTree(p.left,q.left) and isSameTree(p.right,q.right)
-    else :
+    else:
         return False
 ```