摘要：
说明：本文用 \(\phi\) 表示欧拉函数而不用 \(\varphi\)，尽管后者更为常用。\(\DeclareMathOperator{\lcm}{lcm}\) 欧拉函数 \(\phi\colon\mathbb Z_{>0}\to \mathbb Z\) 定义为 \[ \phi(n) = |\{ 阅读全文
「以解决问题为乐」
真的喜欢么？真的喜欢就去做吧。
Lost Boy Calling 。。。。
... Many of these issues are best dealt with at the algorithmic level, rather than by "tweaking" the code.
This is an obscurity that catches the unwary.
原来我什么都不懂。