摘要：
Give a set S, |S| = n, then how many ordered set group (S1, S2, ..., Sk) satisfies S1 ∩ S2 ∩ ... ∩ Sk = ∅. (Si is a subset of S, (1 <= i <= k)) Input 阅读全文
摘要：
Sky Code Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 2085 Accepted: 665 Description Stancu likes space travels but he is a poor softwar 阅读全文
摘要：
Happy 2006 Time Limit: 3000MS Memory Limit: 65536K Total Submissions: 10856 Accepted: 3776 Description Two positive integers are said to be relatively 阅读全文