摘要：
There are n members in our ACM club. Little W wants to select three persons from our club to form a new team taking part in provincial ACM contests, a 阅读全文
摘要：
Tokitsukaze has a sequence of length n, denoted by a . Tokitsukaze can merge two consecutive elements of a as many times as she wants. After each oper 阅读全文
摘要：
Given a string P consisting of only parentheses and asterisk characters (i.e. "(", ")" and ""), you are asked to replace all the asterisk characters i 阅读全文