Merge pull request #105 from lgylym/patch-1

Add leetcode link to the question

Author: billryan

zh-hans/string/two_strings_are_anagrams.md

@@ -4,6 +4,7 @@ Tags: String, Cracking The Coding Interview, Easy
 
 ## Question
 
+- leetcode: [Valid Anagram](https://leetcode.com/problems/valid-anagram/)
 - lintcode: [Two Strings Are Anagrams](http://www.lintcode.com/en/problem/two-strings-are-anagrams/)
 
 ### Problem Statement