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