摘要：
描述 Jim is fond of reading books, and he has so many books that sometimes it's hard for him to manage them. So he is asking for your help to solve this 阅读全文
摘要：
描述 A subsequence of a given sequence is the given sequence with some elements (possible none) left out. Given a sequence X = <x1, x2, ..., xm> another 阅读全文