数字移位

http://blog.163.com/jiaqiang_wang/blog/static/1188961532009924111934698/

http://canlynet.iteye.com/blog/1796889

http://blog.csdn.net/gaochizhen33/article/details/7161417

http://blog.csdn.net/mustanglau/article/details/4767937

http://blog.csdn.net/housisong/article/details/1616026

http://www.cnblogs.com/yyangblog/archive/2011/01/14/1935656.html