csdn博客链接：https://nuoyanli.blog.csdn.net/article/details/105303017题目链接http://acm.hdu.edu.cn/showproblem.php?pid…

csdn博客链接：https://blog.csdn.net/nuoyanli/article/details/105108013链接https://codeforces.com/problemset/problem/1…