uva202:

https://blog.csdn.net/lecholin/article/details/70163148

uva1589:

https://blog.csdn.net/qq_42191950/article/details/80945685

https://www.jianshu.com/p/a44d0662a070

uva1339:

https://blog.csdn.net/karry_zzj/article/details/72763986

uva489:

https://blog.csdn.net/janeyane/article/details/79439660

https://blog.csdn.net/mr_saltyfish/article/details/54150919

uva133:

https://blog.csdn.net/to_xidianhph_youth/article/details/36535113

 uva213:

https://www.jianshu.com/p/359c3238e98c