2020年6月25日
B. Codeforces Subsequences
摘要： Karl likes Codeforces and subsequences. He wants to find a string of lowercase English letters that contains at least kk subsequences codeforces. Out 阅读全文
posted @ 2020-06-25 00:01 DeaL57 阅读(199) 评论(0) 推荐(0) 编辑