摘要：
You are given a non-negative integern, its decimal representation consists of at most100digits and doesn't contain leading zeroes.Your task is to dete... 阅读全文
摘要：
You are given strings. Your task is to determine if the given stringscontains two non-overlapping substrings "AB" and "BA" (the substrings can go in a... 阅读全文
摘要：
You havenproblems. You have estimated the difficulty of thei-th one as integerci. Now you want to prepare a problemset for a contest, using some of th... 阅读全文