摘要:
Description Once upon a time there was a strange kingdom, the kingdom had n cities which were connected by n directed roads and no isolated city.One d 阅读全文
摘要:
Travel The country frog lives in has n towns which are conveniently numbered by 1,2,…,n . Among n(n−1)2 pairs of towns, m of them are connected by bid 阅读全文
摘要:
Censor frog is now a editor to censor so-called sensitive words (敏感词). She has a long text p . Her job is relatively simple -- just to find the first 阅读全文