摘要： http://poj.org/problem?id=2049 Description Nemo is a naughty boy. One day he went into the deep sea all by himself. Unfortunately, he became lost and 阅读全文

摘要： http://acm.hdu.edu.cn/showproblem.php?pid=1180 Problem Description Hogwarts正式开学以后,Harry发现在Hogwarts里,某些楼梯并不是静止不动的，相反,他们每隔一分钟就变动一次方向. 比如下面的例子里,一开始楼梯在竖直方 阅读全文