送交者: 草绿 于 July 27, 2009 23:53:59:
回答: 换成两个人, 如果两个人都是red hair, 答案是2; 如果一个人是red hair而另一个人是blond hair, 答案是1. When can we be sure that 两个人都是red hair? When can we be sure that 一个人是red hair而另一个人是blond hair? 由 lala 于 July 27, 2009 22:28:05:
The wording of the problem is problematic. 从答案反推，实际上这个问题问的是所有颜色同时取极大值时的最小的可能value。For two people with two colors, 两个颜色同时取极大值时（there is only one configuration for this case,可以省略最小）是 one is red and one is blonde, so the value is 1.