Queue http://m635674608.iteye.com/blog/1739860
http://www.iteye.com/problems/84758
http://blog.csdn.net/cnhzgb/article/details/7009036
http://blog.csdn.net/shijinupc/article/details/7250407
类似经典例题:
http://www.360doc.com/content/11/1014/16/7918039_156170594.shtml
http://www.kaixin001.com/repaste/19240035_4737353386.html
http://blog.csdn.net/dazhong159/article/details/7948327(后3、4题)