摘要：
Given a sequence of positive integers, count all contiguous subsequences (sometimes called substrings, in contrast to subsequences, which may leave ou 阅读全文
摘要：
The ministers of the cabinet were quite upset by the message from the Chief of Security stating that they would all have to change the four-digit room 阅读全文
摘要：
题目意思就是已知n的阶乘，求n。 当输入的阶乘小于10位数的时候，我们可以用long long将字符串转化成数字，直接计算。 而当输入的阶乘很大的时候，我们就可以利用位数去大概的估计n。 阅读全文