写些短文的动机是想用一个更浅显的例子(跟组合群试比较 )解释“优化问题”中的组合概率论方法 ,包括不确定性的数量刻画、信息下界等概念 ,顺便纠正组合群试一文中的打印错误 .问题的提法 :ｎ个重量互不相同的球 ,通过在天平上比较可以确定两个球谁轻谁重 ,问立足于最坏可能 , The motive for writing these essays is to use a simpler example (compared with the group test) to explain the combinatorial probability method in the “optimization problem”, including the concept of quantitative description of the uncertainty, the information lower bound, and the like. In the article, the printing error is wrong. The question is formulated: n balls of different weights can be determined by comparing the balance.