Theorem: Any protocol of date problem has success probability less than which is about . Here is the biggest number such that .
Proof: First, let's introduce some notation. is the set of permutations of .
For any two permutations and , we say if and fit with the first [...]

题外话：最近阅微堂发的都是网友转发的政治方面的文章，不爱看的人会比较痛苦。现在讨论一个轻松一点的话题。其问题，已经被研究了很多年，有许多不同形式的阐述方式和变种，应用范围也很广。下面应该是比较吸引人和简单的那种，来自姚期智教授的理论计算机（I）的授课内容——我是其助教之一。

现假设你在PIE上征友，或者以其它方式，选定了某些约会对...