摘要：
http://poj.org/problem?id=3253 Farmer John wants to repair a small length of the fence around the pasture. He measures the fence and finds that he nee 阅读全文
摘要：
X soldiers from the famous “FFF army'' is standing in a line, from left to right. You, as the captain of FFF, decides to have a number off, that is, e 阅读全文