位运算

参考：

[1]http://blog.csdn.net/yunyu5120/article/details/6692072
[2]http://blog.csdn.net/superdullwolf/article/details/4649080
[3]http://blog.csdn.net/morewindows/article/details/7354571
[4]http://blog.csdn.net/hguisu/article/details/7892596
[5]http://nassir.iteye.com/blog/1994914