leetcode -- Single Number II &III- 位操作，没有理解

Single Number II

https://leetcode.com/problems/single-number-ii/

位操作不熟悉，复习的时候再熟悉一下

参考
http://www.cnblogs.com/zuoyuan/p/3719753.html
http://yucoding.blogspot.hk/2014/10/single-number-ii.html

Single Number III

https://leetcode.com/problems/single-number-iii/

参考
http://bookshadow.com/weblog/2015/08/17/leetcode-single-number-iii/